content: <PAGE>
  
                                                             Registration No. 333-
  
  ================================================================================
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                                ---------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
                                --------------------
  
                                  LIGHTBRIDGE, INC.
               (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
  
  DELAWARE                                                              04-3065140
  (State or Other Jurisdiction of                                 (I.R.S. Employer
  Incorporation or Organization)                               Identification No.)
  
  30 CORPORATE DRIVE                                                         01803
  BURLINGTON, MA                                                        (Zip Code)
  (Address of Principal Executive Offices)
  
                     LIGHTBRIDGE, INC. 2004 STOCK INCENTIVE PLAN
                              (Full Title of the Plan)
  
                                --------------------
  
                                MR. ROBERT E. DONAHUE
                        President and Chief Executive Officer
                                  LIGHTBRIDGE, INC.
                                 30 Corporate Drive
                           Burlington, Massachusetts 01803
                       (NAME AND ADDRESS OF AGENT FOR SERVICE)
  
                                   (781) 359-4000
            (TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE)
  
                                --------------------
  
                                   WITH COPIES TO:
                           John D. Patterson, Jr., Esquire
                             Alexander H. Pyle, Esquire
                                   Foley Hoag LLP
                                155 Seaport Boulevard
                             Boston, Massachusetts 02210
                                   (617) 832-1000
                                --------------------
  <PAGE>
                           CALCULATION OF REGISTRATION FEE
  
  <TABLE>
  <CAPTION>
          TITLE OF                                        PROPOSED               PROPOSED
         SECURITIES                 AMOUNT                MAXIMUM                MAXIMUM              AMOUNT OF
            TO BE                   TO BE              OFFERING PRICE            AGGREGATE           REGISTRATION
         REGISTERED               REGISTERED             PER SHARE            OFFERING PRICE             FEE
         ----------               ----------             ---------            --------------             ---
  <S>                        <C>                       <C>                    <C>                    <C>
  
        Common Stock,        1,574,800(1) (2) (3)         $4.70(4)            $7,401,560.00            $937.78
       $.01 par value
  
        Common Stock,          925,200(2) (3) (5)         $5.02(6)            $4,644,504.00            $588.46
       $.01 par value
  </TABLE>
  
           (1) Represents shares of common stock issuable upon exercise of
  outstanding awards granted under the Lightbridge, Inc. 2004 Stock Incentive Plan
  (the "Plan").
  
           (2) Pursuant to Rule 416(a) under the Securities Act of 1933, the
  number of shares of Common Stock being registered shall be adjusted to include
  any additional shares which may become issuable as a result of stock splits,
  stock dividends, or similar transactions in accordance with the anti-dilution
  provisions of the Lightbridge, Inc. 2004 Stock Incentive Plan, the Lightbridge,
  Inc. 1998 Non-Statutory Stock Option Plan and the Lightbridge, Inc. 1996
  Incentive and Non-Qualified Stock Option Plan.
  
           (3) This Registration Statement also includes an aggregate of 5,350,000
  shares of Common Stock previously registered on Form S-8 Registration Statement
  No. 333-23937, filed on March 25, 1997, Form S-8 Registration Statement No.
  333-67881, filed on November 25, 1998, Form S-8 Registration Statement No.
  333-43588, filed on August 11, 2000, and Form S-8 Registration Statement No.
  333-56774, filed on March 9, 2001. In connection with such previously registered
  shares of Common Stock, the Registrant has paid fees of $2,347, $2,176,
  $8,085.83 and $6,125, respectively. In connection with this Registration
  Statement, the Registrant is paying a fee based solely on the additional
  2,500,000 shares of Common Stock being registered herein.
  
           (4) Calculated pursuant to Rule 457 (h)(1) under the Securities Act of
  1933 based on the average exercise price of awards outstanding under the Plan.
  
           (5) Represents shares of common stock available for issuance pursuant
  to the Plan.
  
           (6) Calculated pursuant to Rule 457(c) and (h)(1) under the Securities
  Act of 1933 based on the average of the high and low sales price of the Common
  Stock as reported on the Nasdaq National Market on October 5, 2004.
  
  ================================================================================
  
                                        -2-
  <PAGE>
                                  EXPLANATORY NOTE
  
           On June 2, 2004, the stockholders of Lightbridge, Inc. ("Lightbridge"
  or the "Registrant") approved Lightbridge's 2004 Stock Incentive Plan (the "2004
  Plan"). The 2004 Plan provides for the issuance of a number of shares of Common
  Stock equal to (i) 2,500,000 shares (the "New Plan Shares"), plus (ii) the
  number of shares remaining available for future grants under Lightbridge's 1998
  Non-Statutory Stock Option Plan and 1996 Incentive and Non-Qualified Stock
  Option Plan (the "Prior Plans") as of the effective date of the 2004 Plan, and
  plus (iii) the number of shares subject to any stock option granted pursuant to
  the Prior Plans that expires, is cancelled or otherwise terminates (other than
  by exercise) after the effective date of the 2004 Plan. The purpose of this
  Registration Statement is to register the New Plan Shares for issuance under the
  2004 Plan. The Registrant previously registered an aggregate of 5,350,000 shares
  authorized for issuance pursuant to the Prior Plans in earlier filed
  registration statements on Form S-8 (Registration Nos. 333-23937, 333-67881,
  333-43588 and 333-56774), the contents of which the Registrant incorporates by
  reference herein for the purposes of General Instruction E to Form S-8.
  
                                        -3-
  <PAGE>
  PART II
  
                 INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  ITEM 8. EXHIBITS.
  
  <TABLE>
  <CAPTION>
           Exhibit No.      Description
           -----------      -----------
  <S>                       <C>
           4.1 (1)          Amended and Restated Certificate of Incorporation of the Registrant
           4.2 (1)          Amended and Restated By-Laws of the Registrant
           4.3 (2)          Amendment to Amended and Restated By-Laws of the Registrant, adopted October 29, 1998
           4.4 (1)          Specimen Certificate for Common Stock of the Registrant
           4.5 (3)          Rights Agreement dated as of November 14, 1997, between Lightbridge, Inc.
                            and American Stock Transfer and Trust Registrant, as Rights Agent
           4.6 (3)          Form of Certificate of Designation of Series A Participating Cumulative
                            Preferred Stock of Lightbridge, Inc.
           4.7 (3)          Form of Right Certificate
           4.8 (4)          Lightbridge, Inc. 2004 Stock Incentive Plan
           5.1*             Opinion of Foley Hoag LLP
           23.1*            Consent of Independent Registered Public Accounting Firm
           23.2*            Consent of Foley Hoag LLP (included in Exhibit 5.1)
           24.1*            Power of Attorney (contained on the signature page)
  </TABLE>
  
  -------------------------------------
  
  *        Filed herewith
  
  (1)      Incorporated by reference from the Registrant's Registration Statement
           on Form S-1, as amended (File No. 333-6589)
  
  (2)      Incorporated by reference from the Registrant's Quarterly Report on
           Form 10-Q for the quarter ended September 30, 1998.
  
  (3)      Incorporated by reference from the Registrant's Registration Statement
           on Form 8-A, as filed with the Securities and Exchange Commission on
           November 21, 1997.
  
  (4)      Incorporated by reference from the Registrant's definitive Proxy
           Statement dated May 3, 2004.
  
                                        -4-
  <PAGE>
                                     SIGNATURES
  
           Pursuant to the requirements of the Securities Act of 1933, 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 TOWN OF BURLINGTON, MASSACHUSETTS, on this 12th day of
  October, 2004.
  
                                     LIGHTBRIDGE, INC.
  
                                     By:      /s/ Robert E. Donahue
                                         ----------------------------------------
                                           Robert E. Donahue
                                           President and Chief Executive Officer
  
                                  POWER OF ATTORNEY
  
           KNOW ALL MEN BY THESE PRESENTS that each individual whose signature
  appears below constitutes and appoints Robert E. Donahue as the undersigned's
  true and lawful attorney-in-fact and agent, with full power of substitution, for
  the undersigned and in the undersigned's 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 all documents in connection therewith, with the Commission, granting unto
  said attorney-in-fact and agent full power and authority to do and perform each
  and every act and thing which she may deem necessary or advisable to be done in
  connection with this Registration Statement, as fully to all intents and
  purposes as the undersigned might or could do in person, hereby ratifying and
  confirming all that said attorney-in-fact and agent, or any substitute or
  substitutes for her, may lawfully do or cause to be done by virtue hereof.
  
           Pursuant to the requirements of the Securities Act, this registration
  statement has been signed by the following persons in the indicated capacities
  on the dates indicated.
  
  <TABLE>
  <CAPTION>
                    SIGNATURE                                      TITLE                               DATE
                    ---------                                      -----                               ----
  <S>                                        <C>                                                 <C>
      /s/ Robert E. Donahue                  President, Chief Executive Officer and              October 12, 2004
  ------------------------------------       Director (Principal Executive Officer)
           Robert E. Donahue
  
     /s/ Timothy C. O'Brien                  Vice President, Finance &                           October 12, 2004
  ------------------------------------       Administration and Chief Financial Officer
           Timothy C. O'Brien                (Principal Financial and Accounting Officer)
  
      /s/ David G. Turner                    Director                                            October 12, 2004
  ------------------------------------
           David G. Turner
  
      /s/ Rachelle B. Chong                  Director                                            October 12, 2004
  ------------------------------------
           Rachelle B. Chong
  
      /s/ Andrew G. Mills                    Director                                            October 12, 2004
  ------------------------------------
           Andrew G. Mills
  
      /s/ Dorothy A. Terrell                 Director                                            October 12, 2004
  ------------------------------------
           Dorothy A. Terrell
  
      /s/ Kevin C. Melia                     Director                                            October 12, 2004
  ------------------------------------
           Kevin C. Melia
  </TABLE>
  
                                        -5-
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "b52032l2sv8.txt", "description": "LIGHTBRIDGE, INC. S-8", "secsgml_size_bytes": 12439}]
metadata_filer: {"company-data": {"conformed-name": "LIGHTBRIDGE INC", "cik": "0001017172", "assigned-sic": "4812", "irs-number": "043065140", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-119707", "film-number": "041076137"}, "business-address": {"street1": "67 S BEDFORD ST", "city": "BURLINGTON", "state": "MA", "zip": "01803", "phone": "6173594000"}, "mail-address": {"street1": "67 SOUTH BEDFORD STREET", "city": "BURLINGTON", "state": "MA", "zip": "01803"}}
text: Registration No. 333-
  
  ================================================================================
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                                ---------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
                                --------------------
  
                                  LIGHTBRIDGE, INC.
               (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
  
  DELAWARE                                                              04-3065140
  (State or Other Jurisdiction of                                 (I.R.S. Employer
  Incorporation or Organization)                               Identification No.)
  
  30 CORPORATE DRIVE                                                         01803
  BURLINGTON, MA                                                        (Zip Code)
  (Address of Principal Executive Offices)
  
                     LIGHTBRIDGE, INC. 2004 STOCK INCENTIVE PLAN
                              (Full Title of the Plan)
  
                                --------------------
  
                                MR. ROBERT E. DONAHUE
                        President and Chief Executive Officer
                                  LIGHTBRIDGE, INC.
                                 30 Corporate Drive
                           Burlington, Massachusetts 01803
                       (NAME AND ADDRESS OF AGENT FOR SERVICE)
  
                                   (781) 359-4000
            (TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE)
  
                                --------------------
  
                                   WITH COPIES TO:
                           John D. Patterson, Jr., Esquire
                             Alexander H. Pyle, Esquire
                                   Foley Hoag LLP
                                155 Seaport Boulevard
                             Boston, Massachusetts 02210
                                   (617) 832-1000
                                --------------------
  CALCULATION OF REGISTRATION FEE
  TITLE OF                                        PROPOSED               PROPOSED
         SECURITIES                 AMOUNT                MAXIMUM                MAXIMUM              AMOUNT OF
            TO BE                   TO BE              OFFERING PRICE            AGGREGATE           REGISTRATION
         REGISTERED               REGISTERED             PER SHARE            OFFERING PRICE             FEE
         ----------               ----------             ---------            --------------             ---
  Common Stock,        1,574,800(1) (2) (3)         $4.70(4)            $7,401,560.00            $937.78
       $.01 par value
  
        Common Stock,          925,200(2) (3) (5)         $5.02(6)            $4,644,504.00            $588.46
       $.01 par value
  (1) Represents shares of common stock issuable upon exercise of
  outstanding awards granted under the Lightbridge, Inc. 2004 Stock Incentive Plan
  (the "Plan").
  
           (2) Pursuant to Rule 416(a) under the Securities Act of 1933, the
  number of shares of Common Stock being registered shall be adjusted to include
  any additional shares which may become issuable as a result of stock splits,
  stock dividends, or similar transactions in accordance with the anti-dilution
  provisions of the Lightbridge, Inc. 2004 Stock Incentive Plan, the Lightbridge,
  Inc. 1998 Non-Statutory Stock Option Plan and the Lightbridge, Inc. 1996
  Incentive and Non-Qualified Stock Option Plan.
  
           (3) This Registration Statement also includes an aggregate of 5,350,000
  shares of Common Stock previously registered on Form S-8 Registration Statement
  No. 333-23937, filed on March 25, 1997, Form S-8 Registration Statement No.
  333-67881, filed on November 25, 1998, Form S-8 Registration Statement No.
  333-43588, filed on August 11, 2000, and Form S-8 Registration Statement No.
  333-56774, filed on March 9, 2001. In connection with such previously registered
  shares of Common Stock, the Registrant has paid fees of $2,347, $2,176,
  $8,085.83 and $6,125, respectively. In connection with this Registration
  Statement, the Registrant is paying a fee based solely on the additional
  2,500,000 shares of Common Stock being registered herein.
  
           (4) Calculated pursuant to Rule 457 (h)(1) under the Securities Act of
  1933 based on the average exercise price of awards outstanding under the Plan.
  
           (5) Represents shares of common stock available for issuance pursuant
  to the Plan.
  
           (6) Calculated pursuant to Rule 457(c) and (h)(1) under the Securities
  Act of 1933 based on the average of the high and low sales price of the Common
  Stock as reported on the Nasdaq National Market on October 5, 2004.
  
  ================================================================================
  
                                        -2-
  EXPLANATORY NOTE
  
           On June 2, 2004, the stockholders of Lightbridge, Inc. ("Lightbridge"
  or the "Registrant") approved Lightbridge's 2004 Stock Incentive Plan (the "2004
  Plan"). The 2004 Plan provides for the issuance of a number of shares of Common
  Stock equal to (i) 2,500,000 shares (the "New Plan Shares"), plus (ii) the
  number of shares remaining available for future grants under Lightbridge's 1998
  Non-Statutory Stock Option Plan and 1996 Incentive and Non-Qualified Stock
  Option Plan (the "Prior Plans") as of the effective date of the 2004 Plan, and
  plus (iii) the number of shares subject to any stock option granted pursuant to
  the Prior Plans that expires, is cancelled or otherwise terminates (other than
  by exercise) after the effective date of the 2004 Plan. The purpose of this
  Registration Statement is to register the New Plan Shares for issuance under the
  2004 Plan. The Registrant previously registered an aggregate of 5,350,000 shares
  authorized for issuance pursuant to the Prior Plans in earlier filed
  registration statements on Form S-8 (Registration Nos. 333-23937, 333-67881,
  333-43588 and 333-56774), the contents of which the Registrant incorporates by
  reference herein for the purposes of General Instruction E to Form S-8.
  
                                        -3-
  PART II
  
                 INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  ITEM 8. EXHIBITS.
  Exhibit No.      Description
           -----------      -----------
  4.1 (1)          Amended and Restated Certificate of Incorporation of the Registrant
           4.2 (1)          Amended and Restated By-Laws of the Registrant
           4.3 (2)          Amendment to Amended and Restated By-Laws of the Registrant, adopted October 29, 1998
           4.4 (1)          Specimen Certificate for Common Stock of the Registrant
           4.5 (3)          Rights Agreement dated as of November 14, 1997, between Lightbridge, Inc.
                            and American Stock Transfer and Trust Registrant, as Rights Agent
           4.6 (3)          Form of Certificate of Designation of Series A Participating Cumulative
                            Preferred Stock of Lightbridge, Inc.
           4.7 (3)          Form of Right Certificate
           4.8 (4)          Lightbridge, Inc. 2004 Stock Incentive Plan
           5.1*             Opinion of Foley Hoag LLP
           23.1*            Consent of Independent Registered Public Accounting Firm
           23.2*            Consent of Foley Hoag LLP (included in Exhibit 5.1)
           24.1*            Power of Attorney (contained on the signature page)
  -------------------------------------
  
  *        Filed herewith
  
  (1)      Incorporated by reference from the Registrant's Registration Statement
           on Form S-1, as amended (File No. 333-6589)
  
  (2)      Incorporated by reference from the Registrant's Quarterly Report on
           Form 10-Q for the quarter ended September 30, 1998.
  
  (3)      Incorporated by reference from the Registrant's Registration Statement
           on Form 8-A, as filed with the Securities and Exchange Commission on
           November 21, 1997.
  
  (4)      Incorporated by reference from the Registrant's definitive Proxy
           Statement dated May 3, 2004.
  
                                        -4-
  SIGNATURES
  
           Pursuant to the requirements of the Securities Act of 1933, 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 TOWN OF BURLINGTON, MASSACHUSETTS, on this 12th day of
  October, 2004.
  
                                     LIGHTBRIDGE, INC.
  
                                     By:      /s/ Robert E. Donahue
                                         ----------------------------------------
                                           Robert E. Donahue
                                           President and Chief Executive Officer
  
                                  POWER OF ATTORNEY
  
           KNOW ALL MEN BY THESE PRESENTS that each individual whose signature
  appears below constitutes and appoints Robert E. Donahue as the undersigned's
  true and lawful attorney-in-fact and agent, with full power of substitution, for
  the undersigned and in the undersigned's 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 all documents in connection therewith, with the Commission, granting unto
  said attorney-in-fact and agent full power and authority to do and perform each
  and every act and thing which she may deem necessary or advisable to be done in
  connection with this Registration Statement, as fully to all intents and
  purposes as the undersigned might or could do in person, hereby ratifying and
  confirming all that said attorney-in-fact and agent, or any substitute or
  substitutes for her, may lawfully do or cause to be done by virtue hereof.
  
           Pursuant to the requirements of the Securities Act, this registration
  statement has been signed by the following persons in the indicated capacities
  on the dates indicated.
  SIGNATURE                                      TITLE                               DATE
                    ---------                                      -----                               ----
  /s/ Robert E. Donahue                  President, Chief Executive Officer and              October 12, 2004
  ------------------------------------       Director (Principal Executive Officer)
           Robert E. Donahue
  
     /s/ Timothy C. O'Brien                  Vice President, Finance &                           October 12, 2004
  ------------------------------------       Administration and Chief Financial Officer
           Timothy C. O'Brien                (Principal Financial and Accounting Officer)
  
      /s/ David G. Turner                    Director                                            October 12, 2004
  ------------------------------------
           David G. Turner
  
      /s/ Rachelle B. Chong                  Director                                            October 12, 2004
  ------------------------------------
           Rachelle B. Chong
  
      /s/ Andrew G. Mills                    Director                                            October 12, 2004
  ------------------------------------
           Andrew G. Mills
  
      /s/ Dorothy A. Terrell                 Director                                            October 12, 2004
  ------------------------------------
           Dorothy A. Terrell
  
      /s/ Kevin C. Melia                     Director                                            October 12, 2004
  ------------------------------------
           Kevin C. Melia
  -5-