<PAGE>


   As filed with the Securities and Exchange Commission on December 22, 2000
                                                     Registration No. 333-47798

================================================================================
                      SECURITIES AND EXCHANGE COMMISSION
                             Washington D.C. 20549

                              Amendment No. 1 to
                                   FORM S-3
            REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
                              __________________
                      FIRST HORIZON ASSET SECURITIES INC.
            (Exact name of registrant as specified in its charter)

           Delaware                                         75-2808384
 (State or other jurisdiction of                         (I.R.S. Employer
 incorporation or organization)                         Identification No.)
                               4000 Horizon Way
                              Irving, Texas 75063
                                (214) 441-4000
         (Address, including zip code, and telephone number, including
            area code, of registrant's principal executive offices)
                            ______________________

                                Gerald L. Baker
                               4000 Horizon Way
                              Irving, Texas 75063
                                (214) 441-4000
           (Name, address, including zip code, and telephone number
                  including area code, of agent for service)
                            ______________________

      The Commission is requested to send copies of all communication to:

<TABLE>
<S>                       <C>                                           <C>
     David Barbour               Clyde A. Billings, Jr.                    John Arnholz
 Andrews & Kurth L.L.P.        Vice President and Counsel                Brown & Wood LLP
    1717 Main Street      First Tennessee National Corporation          1666 K Street, N.W.
       Suite 3700                  165 Madison Avenue                   Washington, DC 20006
  Dallas, Texas 75201           Memphis, Tennessee 38103                   (202) 533-1300
     (214) 659-4400                  (901) 523-5679
</TABLE>

     Approximate date of commencement of proposed sale to the public: From time
to time after the effective date of this Registration Statement, as determined
by market conditions.

     If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box.[_]

     If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or
reinvestment plans, please check the following box.[X]

     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering.[_]

     If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration for the same
offering.[_]

     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box.[_]

<TABLE>
<CAPTION>
                                      CALCULATION OF REGISTRATION FEE
======================================================================================================================
                                                             Proposed maximum     Proposed maximum       Amount of
 Title of each class of securities to       Amount to be      offering price          aggregate         registration
          be registered                     registered(1)       per unit(2)       offering price(2)        fee(2)(3)
----------------------------------------------------------------------------------------------------------------------
<S>                                         <C>              <C>                  <C>                   <C>
Mortgage and Asset Backed Securities     $1,000,000,000             100%           $1,000,000,000          $250,000
======================================================================================================================
</TABLE>

(1)  This Registration Statement relates to the offering from time to time of up
     to $1,000,000,000 aggregate principal amount of Asset Backed Securities and
     to any resales of them in market making transactions by First Tennessee
     Securities Corporation or First Tennessee Capital Markets, each an
     affiliate of the Registrant, to the extent required.
(2)  Estimated for the purpose of calculating the registration fee pursuant to
     Rule 457(o).
(3)  $264.00 of which was previously paid to the commission on October 12, 2000
     in connection with the filing of the Registration Statement.
                             __________________

     Pursuant to Rule 429 under the Securities Act, the Prospectus which is part
of this Registration Statement is a combined Prospectus that also relates to
$213,732,964 of Asset Backed Certificates registered under the Registrant's
Registration Statement No. 333-74467 and remaining unissued as of the date
hereof.


                               EXPLANATORY NOTE

     The purpose of this Amendment No. 1 to the Registration Statement is to
increase the Amount to be Registered set forth on the cover page of the
Registration Statement and to provide the information required under Item 14 of
Part II of the Registration Statement.

                                      ii
<PAGE>

                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 14. Other Expenses of Issuance and Distribution

     Set forth below is an estimate of the amount of fees and expenses to be
incurred in connection with the issuance and distribution of the securities
offered hereby, other than underwriting discounts and commissions.

SEC Registration Fee...................... $  250,000
Printing and Engraving Expenses...........      7,500
Accounting Fees and Expenses..............    137,500
Legal Fees and Expenses...................    250,000
Trustee Fees and Expenses.................     50,000
Rating Agency Fees........................    500,000
Miscellaneous.............................     50,000
                                           ----------
          Total........................... $1,245,000
                                           ----------



Item 15. Indemnification of Directors and Officers.

     Section 145 of the Delaware General Corporation Law, as amended, provides
that a corporation may indemnify any person who was or is a party or is
threatened to be made a party to any threatened, pending or completed action or
proceeding, whether civil, criminal, administrative or investigative, by reason
of the fact that he is or was a director, officer, employee or agent of the
corporation or is or was serving at its request in such capacity in another
corporation or business association, against expenses (including attorneys'
fees), judgments, fines and amounts paid in settlement actually and reasonably
incurred by him in connection with such action, suit or proceeding if he acted
in good faith and in a manner he reasonably believed to be in or not opposed to
the best interests of the corporation, and, with respect to any criminal action
or proceeding, had no reasonable cause to believe his conduct was unlawful.

     As permitted by Section 102(b)(7) of the Delaware General Corporation Law,
as amended, the Registrant's Certificate of Incorporation provides that a
director of the Registrant shall not be personally liable to the Registrant or
its stockholders for monetary damages for breach of fiduciary duty as a
director, except for liability (i) for any breach of the director's duty of
loyalty to the corporation or its stockholders, (ii) for acts or omissions not
in good faith or which involve intentional misconduct or a knowing violation of
law, (iii) under Section 174 of the Delaware General Corporation Law, or ( iv)
for any transaction from which the director derived an improper personal
benefit.

     The Registrant's Certificate of Incorporation and Bylaws provide that the
Registrant will indemnify each person who is or was a director or officer of the
Registrant to the maximum extent permitted from time to time by law.

     First Tennessee National Corporation, the indirect parent of First Horizon
Asset Securities Inc., provides insurance from commercial carriers against
certain liabilities incurred by its officers and directors and by the officers
and directors of certain of its subsidiaries and other affiliated corporations.

     See Item 17(c) below.

                                     II-1
<PAGE>

Item 16. Exhibits.

     Exhibit No.
     -----------

     1.1  Form of Underwriting Agreement***
     3.1  Certificate of Incorporation*
     3.2  Bylaws*
     4.1  Form of Pooling and Servicing Agreement for Mortgage Pass-Through
          Certificates**
     4.2  Form of Indenture****
     4.3  Form of Trust Agreement****
     5.1  Opinion of Andrews & Kurth L.L.P. regarding legality of the
          Securities****
     8.1  Opinion of Andrews & Kurth L.L.P., regarding certain tax matters****
     10.1 Form of Sale and Servicing Agreement****
     23.1 Consents of Andrews & Kurth L.L.P. (contained in their opinions filed
          as Exhibits 5.1 and 8.1 to this Registration Statement)****
     24.1 Powers of Attorney****
______________
* Previously filed with the Commission on March 16, 1999 as an Exhibit to the
Registrant's Registration Statement on Form S-3 (No. 333-74467)

** Previously filed with the Commission on May 20, 1999 as an Exhibit to
Amendment No. 1 to the Registrant's Registration Statement on Form S-3 (No. 333-
74467)

*** Previously filed with the Commission on December 20, 1999 as an Exhibit to
Amendment No. 3 to the Registrant's Registration Statement on Form S-3 (No.
333-74467).

****Previously filed with the Commission on October 12, 2000 as an Exhibit to
the Registrant's Registration Statement on Form S-3 (No. 333-47798)

Item 17. Undertakings

        (a)    The undersigned registrant hereby undertakes:

               (1)   To file, during any period in which offers or sales are
     being made of the securities registered hereby, a post-effective amendment
     to this registration statement:

               (i)   to include any prospectus required by Section 10(a)(3) of
            the Securities Act of 1933;

               (ii)  to reflect in the prospectus any facts or events arising
            after the effective date of this registration statement (or the most
            recent post-effective amendment hereof) which, individually or in
            the aggregate, represent a fundamental change in the information set
            forth in this registration statement; and

               (iii) to include any material information with respect to the
            plan of distribution not previously disclosed in this registration
            statement or any material change to such information in this
            registration statement.

        Provided, however, that the undertakings set forth in clauses (i) and
        (ii) above do not apply if the information required to be included in a
        post-effective amendment by those clauses is contained in periodic
        reports filed with or furnished to the Commission by the registrant
        pursuant to Section 13 or Section 15(d) of the Securities Exchange Act
        of 1934 that are incorporated by reference in this registration
        statement.

            (2)  That, for the purpose of determining any liability under the
        Securities Act of 1933, each such post-effective amendment shall be
        deemed to be a new registration statement relating to the securities
        offered therein, and the offering of such securities at that time shall
        be deemed to be the initial bona fide offering thereof.

            (3)  To remove from registration by means of a post-effective
        amendment any of the securities being registered which remain unsold at
        the termination of the offering.

        (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 that is incorporated by reference in this
registration statement shall be deemed to be a new registration statement
relating to the securities offered herein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

        (c) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the registrant pursuant to the provisions described under Item 15
above, or otherwise, the registrant has been advised that in the opinion of the
Securities and Exchange Commission such indemnification is against public policy
as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In
the event that a claim for indemnification against such liabilities (other than
the payment by the registrant of expenses incurred or paid by a director,
officer or controlling person of the registrant in the successful defense of any
action, suit or proceeding) is asserted by such director, officer or controlling
person in

                                     II-2
<PAGE>

connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act of 1933 and will be governed by the final adjudication of such issue.

                                     II-3
<PAGE>

                                  SIGNATURES

    Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that (i) it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and (ii) it reasonably believes that the
security rating requirement of Transaction Requirement B.5 of Form S-3 will be
met by the time of sale of each series of securities to which this Amendment No.
1 to Registration Statement relates and has duly caused this Amendment No. 1 to
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Irving, State of Texas, on the 22nd day of
December, 2000.

                                  FIRST HORIZON ASSET SECURITIES INC.



                                  By: /s/ Gerald L. Baker
                                     ---------------------------------
                                      Gerald L. Baker, President and
                                      Chief Executive Officer



    Pursuant to the requirements of the Securities Act of 1933, as amended, this
Amendment No. 1 to 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>
                                                  President
  /s/ Gerald L. Baker                Chief Executive Officer and Director       December 22, 2000
---------------------------------
      Gerald L. Baker                   (Principal Executive Officer)

  /s/ Peter F. Makowiecki                Chief Financial Officer and            December 22, 2000
---------------------------------                 Treasurer
      Peter F. Makowiecki              (Principal Financial Officer and
                                         Principal Accounting Officer)

      J. Kenneth Glass*                            Director                     December 22, 2000
---------------------------------
      J. Kenneth Glass

     Thomas J. Wageman*                            Director                     December 22, 2000
---------------------------------
     Thomas J. Wageman

*By:   /s/ Gerald L. Baker
    -----------------------------
           Gerald L. Baker
          Attorney-in-Fact
</TABLE>

                                     II-4
<PAGE>

                               INDEX TO EXHIBITS

    Exhibit No.
    -----------

    1.1        Form of Underwriting Agreement***
    3.1        Certificate of Incorporation*
    3.2        Bylaws*
    4.1        Form of Pooling and Servicing Agreement for Mortgage Pass-Through
               Certificates**
    4.2        Form of Indenture****
    4.3        Form of Trust Agreement****
    5.1        Opinion of Andrews & Kurth L.L.P. regarding legality of the
               Securities****
    8.1        Opinion of Andrews & Kurth L.L.P., regarding certain tax
               matters****
    10.1       Form of Sale and Servicing Agreement****
    23.1       Consents of Andrews & Kurth L.L.P. (contained in their opinions
               filed as Exhibits 5.1 and 8.1 to this Registration Statement)****
    24.1       Powers of Attorney****
______________
* Previously filed with the Commission on March 16, 1999 as an Exhibit to the
Registrant's Registration Statement on Form S-3 (No. 333-74467)

** Previously filed with the Commission on May 20, 1999 as an Exhibit to
Amendment No. 1 to the Registrant's Registration Statement on Form S-3 (No. 333-
74467)

*** Previously filed with the Commission on December 20, 1999 as an Exhibit to
Amendment No. 3 to the Registrant's Registration Statement on Form S-3 (No.
333-74467).

****Previously filed with the Commission on October 12, 2000 as an Exhibit to
the Registrant's Registration Statement on Form S-3 (No. 333-47798).