content: <PAGE>   1
   As filed with the Securities and Exchange Commission on February 12, 1999 
                                                 Registration No. 333-__________
  ==============================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                                  ----------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
  
                                  ----------------
  
  
                                    ANESTA CORP.
                -----------------------------------------------------
               (Exact name of registrant as specified in its charter)
  
  
          DELAWARE                                       87-0424798
  (State of Incorporation)                (I.R.S. Employer of Identification No.)
  
                                 4745 WILEY POST WAY
                                 PLAZA 6, SUITE 650
                             SALT LAKE CITY, UTAH 84116
                                   (801) 595-1405
                -----------------------------------------------------
            (Address and telephone number of principal executive offices)
  
  
                               1993 STOCK OPTION PLAN
                -----------------------------------------------------
                              (Full title of the plan)
  
  
                                   THOMAS B. KING
                        PRESIDENT AND CHIEF EXECUTIVE OFFICER
                                    ANESTA CORP.
                                 4745 WILEY POST WAY
                                 PLAZA 6, SUITE 650
                             SALT LAKE CITY, UTAH 84116
                                   (801) 595-1405
                ----------------------------------------------------
      (Name, address, including zip code, and telephone number, including area
                            code, of agent for service)
  
                                  ----------------
  
                                     Copies to:
                              JAMES C.T. LINFIELD, ESQ.
                                 COOLEY GODWARD LLP
                          2595 CANYON BOULEVARD, SUITE 250
                            BOULDER, COLORADO 80302-6737
                                   (303) 546-4000
  
                                  ----------------
  
  
                           Exhibit Index appears on Page 4
  
  
  <PAGE>   2
  
  
  
  
  <TABLE>
  <CAPTION>
                                                    CALCULATION OF REGISTRATION FEE
  ==================================================================================================================================
  
  ------------------------------- ------------------------- ------------------------- -------------------------  -------------------
                                                                PROPOSED MAXIMUM          PROPOSED MAXIMUM
         TITLE OF SECURITIES TO   AMOUNT TO BE REGISTERED      OFFERING PRICE PER        AGGREGATE OFFERING          AMOUNT OF
             BE REGISTERED                                         SHARE (1)                 PRICE (1)           REGISTRATION FEE
  ------------------------------- ------------------------- ------------------------- -------------------------  -------------------
  
  <S>                           <C>                             <C>                      <C>                     <C>  
        Stock   Options  and
        Common  Stock    (par 
        value $.001)                            200,000           $25.00                    $2,626,116.47             $730.06
  
  ------------------------------- ------------------------- ------------------------- -------------------------  -------------------
  
  ==================================================================================================================================
  </TABLE>
  
  (1)      Estimated solely for the purpose of calculating the amount of the
           registration fee, pursuant to Rule 457(h) under the Securities Act of
           1933, as amended (the "Act") The offering price per share and aggregate
           offering price are based on (a) the weighted average exercise price for
           shares subject to options previously granted under the Registrant's
           1993 Stock Option Plan, as amended and (b) the price per share and
           aggregate offering price based upon the closing price of Registrant's
           Common Stock on February 11, 1999 as reported on the Nasdaq National
           Market for options and shares to be granted under the 1993 Stock Option
           Plan, as amended. The following chart illustrates the calculation of
           the registration fee:
  <TABLE>
  <CAPTION>
  ==================================================================================================================================
              TYPE OF SHARES            NUMBER OF SHARES         OFFERING PRICE PER SHARE           AGGREGATE OFFERING PRICE
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
  
  <S>                                 <C>                       <C>                                <C> 
        Shares issuable pursuant
        to options outstanding
        under the 1993 Stock                182,747                             $12.01(a)              $2,194,791.47
        Option Plan, as amended
  
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
        Shares issuable upon
        exercise of options
        available for grant under
        the 1993 Stock  Option               17,253                             $25.00(b)              $  431,325.00
        Plan, as amended
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
        Proposed Maximum  Aggregate                                                                    $2,626,116.47
        Offering Price
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
                                                                                                             .000278
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
        Registration Fee                                                                               $      730.06
  ==================================================================================================================================
  </TABLE>
  
           (a) Weighted average exercise price.
  
           (b) Nasdaq National Market closing price of the Registrant's Common
               Stock on February 11, 1999.
  
  
  ==============================================================================
  
           Approximate date of commencement of proposed sale to the public: As
  soon as practicable after this Registration Statement becomes effective.
  
  
                                         2.
  
  <PAGE>   3
  
  
  
  
                                       PART I
  
  ITEM 1.  PLAN INFORMATION
  
           Not required to be filed with this Registration Statement.
  
  ITEM 2.  REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION
  
           Not required to be filed with this Registration Statement.
  
                                       PART II
  
  ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE
  
           The following documents filed by Anesta Corp., a Delaware corporation
  (the "Company" or the "Registrant") with the Securities and Exchange Commission
  (the "Commission") are incorporated by reference into this Registration
  Statement:
  
           (a) The Registration Statement on Form S-8 No. 33-74650 filed on
  February 1, 1994;
  
           (b) The Registration Statement on Form S-8 No. 33-31565 filed on July
  18, 1997;
  
           (c) The Company's latest annual report on Form 10-K for the fiscal year
  ended December 31, 1997;
  
           (d) The Company's latest quarterly report on Form 10-Q for the quarter
  ended March 31, 1998;
  
           (e) The Company's latest quarterly report on Form 10-Q and Form 10-Q/A
  for the quarter ended June 30, 1998;
  
           (f) The Company's latest quarterly report on Form 10-Q and Form 10-Q/A
  for the quarter ended September 30, 1998;
  
           (f) A description of the Company's Common Stock, which is contained in
  the Form 8-A Registration Statement filed by the Company with the Commission
  which was declared effective on January 27, 1994; and
  
           (g) All reports and other documents subsequently filed by the Company
  pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
  of 1934, as amended (the "Exchange Act") prior to the filing of a post-effective
  amendment which indicates that all securities offered have been sold or which
  deregisters all securities remaining unsold, shall be deemed to be incorporated
  by reference herein and to be a part of this registration statement from the
  date of the filing of such reports and documents.
  
  ITEM 4.  DESCRIPTION OF SECURITIES
  
           Not required to be filed with this Registration Statement.
  
  ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL
  
           Not applicable.
  
  ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS
  
           Not required to be filed with this Registration Statement.
  
  ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED
  
           Not applicable.
  
  
  
  
                                         3.
  
  <PAGE>   4
  
  
  
  ITEM 8.  CONSULTANTS AND ADVISORS
  
           Not applicable.
  
  ITEM 9.  EXHIBITS
  
                                      EXHIBITS
  <TABLE>
  <CAPTION>
  EXHIBIT
  NUMBER
  -------
  
  <S>              <C>                              
  5.1              Opinion of Cooley Godward LLP.
  
  23.1             Consent of PricewaterhouseCoopers LLP
  
  23.2             Consent of Cooley Godward LLP is contained in Exhibit 5.1 to 
                   this Registration Statement.
  
  24.1             Power of Attorney is contained on the signature pages.
  
  99.5             Registrant's 1993 Stock Option Plan, as amended.
  </TABLE>
  
  
  ITEM 10. UNDERTAKINGS
  
           Not required to be filed with this Registration Statement.
  
  
  
  
                                         4.
  
  <PAGE>   5
  
  
  
                                     SIGNATURES
  
           Pursuant to the requirements of the Securities Act of 1933, as amended,
  the Registrant certifies that it has reasonable grounds to believe that it meets
  all of the requirements for filing on Form S-8 and has duly caused this
  Registration Statement to be signed on its behalf by the undersigned, thereunto
  duly authorized, in the City of Salt Lake City, State of Utah, on February 12,
  1999.
  
                                          ANESTA CORP.
  
  
  
                                          By /s/ Thomas B. King
                                             -----------------------------------
                                             Thomas B. King
                                             President and Chief Executive Officer
  
  
  
  
  
                                  POWER OF ATTORNEY
  
  
           KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
  appears below constitutes and appoints Thomas B. King and Roger P. Evans, and
  each or any one of them, his true and lawful attorney-in-fact and agent, with
  full power of substitution and resubstitution, for him and in his name, place
  and stead, in any and all capacities, to sign any and all amendments (including
  post-effective amendments) to this Registration Statement, and to file the same,
  with all exhibits thereto, and other documents in connection therewith, with the
  Securities and Exchange Commission, granting unto said attorneys-in-fact and
  agents, and each of them, full power and authority to do and perform each and
  every act and thing requisite and necessary to be done in connection therewith,
  as fully to all intents and purposes as he might or could do in person, hereby
  ratifying and confirming all that said attorneys-in-fact and agents, or any of
  them, or their or his substitutes or substitute, may lawfully do or cause to be
  done by virtue hereof.
  
  
                                         5.
  
  <PAGE>   6
  
  
  
           Pursuant to the requirements of the Securities Act of 1933, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated.
  
  <TABLE>
  <CAPTION>
  SIGNATURE                                              TITLE                                   DATE
  <S>            <C>                                     <C>                                     <C> 
                 /s/ William C. Moeller                  Chairman of the Board, Treasurer and        February 12, 1999
  -----------------------------------------------------  Director (Principal Financial Officer)
                   William C. Moeller
  
  
                   /s/ Thomas B. King                    President, Chief Executive Officer          February 12, 1999
  -----------------------------------------------------  and Director (Principal Executive
                     Thomas B. King                      Officer)
  
  
                 /s/ Theodore H. Stanley                 Founding Chairman and Secretary             February 12, 1999
  -----------------------------------------------------
                Theodore H. Stanley, M.D.
  
  
                   /s/ Roger P. Evans                    Vice President, Finance and                 February 12, 1999
  -----------------------------------------------------  Administration (Principal Accounting
                     Roger P. Evans                      Officer)
  
  
                 /s/ Edwin M. Kania, Jr.                 Director                                    February 12, 1999
  -----------------------------------------------------
                   Edwin M. Kania, Jr.
  
  
                  /s/ Daniel L. Kisner                   Director                                    February 12, 1999
  -----------------------------------------------------
                 Daniel L. Kisner, M.D.
  
  
                  /s/ Richard H. Leazer                  Director                                    February 12, 1999
  -----------------------------------------------------
                    Richard H. Leazer
  
  
                  /s/ Emanuel M. Papper                  Director                                    February 12, 1999
  -----------------------------------------------------
             Emanuel M. Papper, M.D., Ph.D.
  
  
                  /s/ Richard P. Urfer                   Director                                    February 12, 1999
  -----------------------------------------------------
                    Richard P. Urfer
  </TABLE>
  
  
  
                                         6.
  
  <PAGE>   7
  
  
  
                                    EXHIBIT INDEX
  
  <TABLE>
  <CAPTION>
  EXHIBIT
  NUMBER                       DESCRIPTION                      SEQUENTIAL PAGE NUMBER
  -------                      -----------                      ----------------------
  <S>      <C>                                                  <C>
   5.1      Opinion of Cooley LLP
  
  23.1      Consent of PricewaterhouseCoopers LLP
   
  23.2      Consent of Cooley  Godward  LLP is  contained  in  Exhibit 5.1  to 
            this Registration Statement.
  
  24.1      Power of Attorney is contained on the signature pages. 
  
  99.5      Registrant's 1993 Stock Option Plan, as amended.
  </TABLE>
  
  
                                         7.
metadata_documents: [{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 15557}]
metadata_filer: {"company-data": {"conformed-name": "ANESTA CORP /DE/", "cik": "0000915916", "assigned-sic": "2834", "irs-number": "870424798", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-72281", "film-number": "99536160"}, "business-address": {"street1": "4745 WILEY POST WAY", "street2": "STE 650", "city": "SALT LAKE CITY", "state": "UT", "zip": "84116", "phone": "8015951405"}, "mail-address": {"street1": "4745 WILEY POST WAY", "street2": "SUITE 650", "city": "SALT LAKE CITY", "state": "UT", "zip": "84116"}}
text: 1
   As filed with the Securities and Exchange Commission on February 12, 1999 
                                                 Registration No. 333-__________
  ==============================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                                  ----------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
  
                                  ----------------
  
                                    ANESTA CORP.
                -----------------------------------------------------
               (Exact name of registrant as specified in its charter)
  
          DELAWARE                                       87-0424798
  (State of Incorporation)                (I.R.S. Employer of Identification No.)
  
                                 4745 WILEY POST WAY
                                 PLAZA 6, SUITE 650
                             SALT LAKE CITY, UTAH 84116
                                   (801) 595-1405
                -----------------------------------------------------
            (Address and telephone number of principal executive offices)
  
                               1993 STOCK OPTION PLAN
                -----------------------------------------------------
                              (Full title of the plan)
  
                                   THOMAS B. KING
                        PRESIDENT AND CHIEF EXECUTIVE OFFICER
                                    ANESTA CORP.
                                 4745 WILEY POST WAY
                                 PLAZA 6, SUITE 650
                             SALT LAKE CITY, UTAH 84116
                                   (801) 595-1405
                ----------------------------------------------------
      (Name, address, including zip code, and telephone number, including area
                            code, of agent for service)
  
                                  ----------------
  
                                     Copies to:
                              JAMES C.T. LINFIELD, ESQ.
                                 COOLEY GODWARD LLP
                          2595 CANYON BOULEVARD, SUITE 250
                            BOULDER, COLORADO 80302-6737
                                   (303) 546-4000
  
                                  ----------------
  
                           Exhibit Index appears on Page 4
  2
  CALCULATION OF REGISTRATION FEE
  ==================================================================================================================================
  
  ------------------------------- ------------------------- ------------------------- -------------------------  -------------------
                                                                PROPOSED MAXIMUM          PROPOSED MAXIMUM
         TITLE OF SECURITIES TO   AMOUNT TO BE REGISTERED      OFFERING PRICE PER        AGGREGATE OFFERING          AMOUNT OF
             BE REGISTERED                                         SHARE (1)                 PRICE (1)           REGISTRATION FEE
  ------------------------------- ------------------------- ------------------------- -------------------------  -------------------
  Stock   Options  and
        Common  Stock    (par 
        value $.001)                            200,000           $25.00                    $2,626,116.47             $730.06
  
  ------------------------------- ------------------------- ------------------------- -------------------------  -------------------
  
  ==================================================================================================================================
  (1)      Estimated solely for the purpose of calculating the amount of the
           registration fee, pursuant to Rule 457(h) under the Securities Act of
           1933, as amended (the "Act") The offering price per share and aggregate
           offering price are based on (a) the weighted average exercise price for
           shares subject to options previously granted under the Registrant's
           1993 Stock Option Plan, as amended and (b) the price per share and
           aggregate offering price based upon the closing price of Registrant's
           Common Stock on February 11, 1999 as reported on the Nasdaq National
           Market for options and shares to be granted under the 1993 Stock Option
           Plan, as amended. The following chart illustrates the calculation of
           the registration fee:
  ==================================================================================================================================
              TYPE OF SHARES            NUMBER OF SHARES         OFFERING PRICE PER SHARE           AGGREGATE OFFERING PRICE
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
  Shares issuable pursuant
        to options outstanding
        under the 1993 Stock                182,747                             $12.01(a)              $2,194,791.47
        Option Plan, as amended
  
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
        Shares issuable upon
        exercise of options
        available for grant under
        the 1993 Stock  Option               17,253                             $25.00(b)              $  431,325.00
        Plan, as amended
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
        Proposed Maximum  Aggregate                                                                    $2,626,116.47
        Offering Price
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
                                                                                                             .000278
  ---------------------------------- ------------------------ ------------------------------- --------------------------------------
        Registration Fee                                                                               $      730.06
  ==================================================================================================================================
  (a) Weighted average exercise price.
  
           (b) Nasdaq National Market closing price of the Registrant's Common
               Stock on February 11, 1999.
  
  ==============================================================================
  
           Approximate date of commencement of proposed sale to the public: As
  soon as practicable after this Registration Statement becomes effective.
  
                                         2.
  3
  
                                       PART I
  
  ITEM 1.  PLAN INFORMATION
  
           Not required to be filed with this Registration Statement.
  
  ITEM 2.  REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION
  
           Not required to be filed with this Registration Statement.
  
                                       PART II
  
  ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE
  
           The following documents filed by Anesta Corp., a Delaware corporation
  (the "Company" or the "Registrant") with the Securities and Exchange Commission
  (the "Commission") are incorporated by reference into this Registration
  Statement:
  
           (a) The Registration Statement on Form S-8 No. 33-74650 filed on
  February 1, 1994;
  
           (b) The Registration Statement on Form S-8 No. 33-31565 filed on July
  18, 1997;
  
           (c) The Company's latest annual report on Form 10-K for the fiscal year
  ended December 31, 1997;
  
           (d) The Company's latest quarterly report on Form 10-Q for the quarter
  ended March 31, 1998;
  
           (e) The Company's latest quarterly report on Form 10-Q and Form 10-Q/A
  for the quarter ended June 30, 1998;
  
           (f) The Company's latest quarterly report on Form 10-Q and Form 10-Q/A
  for the quarter ended September 30, 1998;
  
           (f) A description of the Company's Common Stock, which is contained in
  the Form 8-A Registration Statement filed by the Company with the Commission
  which was declared effective on January 27, 1994; and
  
           (g) All reports and other documents subsequently filed by the Company
  pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
  of 1934, as amended (the "Exchange Act") prior to the filing of a post-effective
  amendment which indicates that all securities offered have been sold or which
  deregisters all securities remaining unsold, shall be deemed to be incorporated
  by reference herein and to be a part of this registration statement from the
  date of the filing of such reports and documents.
  
  ITEM 4.  DESCRIPTION OF SECURITIES
  
           Not required to be filed with this Registration Statement.
  
  ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL
  
           Not applicable.
  
  ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS
  
           Not required to be filed with this Registration Statement.
  
  ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED
  
           Not applicable.
  
                                         3.
  4
  
  ITEM 8.  CONSULTANTS AND ADVISORS
  
           Not applicable.
  
  ITEM 9.  EXHIBITS
  
                                      EXHIBITS
  EXHIBIT
  NUMBER
  -------
  5.1              Opinion of Cooley Godward LLP.
  
  23.1             Consent of PricewaterhouseCoopers LLP
  
  23.2             Consent of Cooley Godward LLP is contained in Exhibit 5.1 to 
                   this Registration Statement.
  
  24.1             Power of Attorney is contained on the signature pages.
  
  99.5             Registrant's 1993 Stock Option Plan, as amended.
  ITEM 10. UNDERTAKINGS
  
           Not required to be filed with this Registration Statement.
  
                                         4.
  5
  
                                     SIGNATURES
  
           Pursuant to the requirements of the Securities Act of 1933, as amended,
  the Registrant certifies that it has reasonable grounds to believe that it meets
  all of the requirements for filing on Form S-8 and has duly caused this
  Registration Statement to be signed on its behalf by the undersigned, thereunto
  duly authorized, in the City of Salt Lake City, State of Utah, on February 12,
  1999.
  
                                          ANESTA CORP.
  
                                          By /s/ Thomas B. King
                                             -----------------------------------
                                             Thomas B. King
                                             President and Chief Executive Officer
  
                                  POWER OF ATTORNEY
  
           KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
  appears below constitutes and appoints Thomas B. King and Roger P. Evans, and
  each or any one of them, his true and lawful attorney-in-fact and agent, with
  full power of substitution and resubstitution, for him and in his name, place
  and stead, in any and all capacities, to sign any and all amendments (including
  post-effective amendments) to this Registration Statement, and to file the same,
  with all exhibits thereto, and other documents in connection therewith, with the
  Securities and Exchange Commission, granting unto said attorneys-in-fact and
  agents, and each of them, full power and authority to do and perform each and
  every act and thing requisite and necessary to be done in connection therewith,
  as fully to all intents and purposes as he might or could do in person, hereby
  ratifying and confirming all that said attorneys-in-fact and agents, or any of
  them, or their or his substitutes or substitute, may lawfully do or cause to be
  done by virtue hereof.
  
                                         5.
  6
  
           Pursuant to the requirements of the Securities Act of 1933, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated.
  SIGNATURE                                              TITLE                                   DATE
  /s/ William C. Moeller                  Chairman of the Board, Treasurer and        February 12, 1999
  -----------------------------------------------------  Director (Principal Financial Officer)
                   William C. Moeller
  
                   /s/ Thomas B. King                    President, Chief Executive Officer          February 12, 1999
  -----------------------------------------------------  and Director (Principal Executive
                     Thomas B. King                      Officer)
  
                 /s/ Theodore H. Stanley                 Founding Chairman and Secretary             February 12, 1999
  -----------------------------------------------------
                Theodore H. Stanley, M.D.
  
                   /s/ Roger P. Evans                    Vice President, Finance and                 February 12, 1999
  -----------------------------------------------------  Administration (Principal Accounting
                     Roger P. Evans                      Officer)
  
                 /s/ Edwin M. Kania, Jr.                 Director                                    February 12, 1999
  -----------------------------------------------------
                   Edwin M. Kania, Jr.
  
                  /s/ Daniel L. Kisner                   Director                                    February 12, 1999
  -----------------------------------------------------
                 Daniel L. Kisner, M.D.
  
                  /s/ Richard H. Leazer                  Director                                    February 12, 1999
  -----------------------------------------------------
                    Richard H. Leazer
  
                  /s/ Emanuel M. Papper                  Director                                    February 12, 1999
  -----------------------------------------------------
             Emanuel M. Papper, M.D., Ph.D.
  
                  /s/ Richard P. Urfer                   Director                                    February 12, 1999
  -----------------------------------------------------
                    Richard P. Urfer
  6.
  7
  
                                    EXHIBIT INDEX
  EXHIBIT
  NUMBER                       DESCRIPTION                      SEQUENTIAL PAGE NUMBER
  -------                      -----------                      ----------------------
  5.1      Opinion of Cooley LLP
  
  23.1      Consent of PricewaterhouseCoopers LLP
   
  23.2      Consent of Cooley  Godward  LLP is  contained  in  Exhibit 5.1  to 
            this Registration Statement.
  
  24.1      Power of Attorney is contained on the signature pages. 
  
  99.5      Registrant's 1993 Stock Option Plan, as amended.
  7.