As filed with the Securities and Exchange Commission on September 21, 2005
                                   Registration Nos. 333-85268
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                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                             ----------------------

                        POST-EFFECTIVE AMENDMENT NO. 1 TO
                                    FORM S-8
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933
                           --------------------------


                             ESCO TECHNOLOGIES INC.
             (Exact Name of Registrant as Specified in Its Charter)

       Missouri                                             43-1554045
(State or Other Jurisdiction of Incorporation            (I.R.S. Employer )
 or Organization)                                         Identification No.

                               9900A Clayton Road
                            St. Louis, MO 63124-1186
          (Address of Principal Executive Offices, Including Zip Code)
          ------------------------------------------------------------

                ESCO TECHNOLOGIES INC. 2001 STOCK INCENTIVE PLAN
             ESCO TECHNOLOGIES INC. 2004 INCENTIVE COMPENSATION PLAN
                            (Full title of the Plan)

                             Alyson S. Barclay, Esq.
                  Vice President, Secretary and General Counsel
                             ESCO Technologies Inc.
                               9900A Clayton Road
                            St. Louis, MO 63124-1186
                                 (314) 213-7200
 (Name, Address and Telephone Number, Including Area Code, of Agent For Service)
 -------------------------------------------------------------------------------

EXPLANATORY NOTE This Post-Effective Amendment to the ESCO Technologies Inc. (the "Company") Registration Statements on Form S-8 (Nos. 333-117953 and 333-85268) (the "Registration Statements"), which relate to the Company's equity-based employee benefit plans, is filed by the Company pursuant to Rule 416(b) under the Securities Act of 1933, as amended (the "Securities Act"), to reflect a one hundred percent increase in the number of shares of common stock, $0.01 par value, of the Company (the "Common Stock") covered by such Registration Statements as a result of the Company's two-for-one stock split effected in the form of a one hundred percent stock dividend payable September 23, 2005, to shareholders of record on September 9, 2005. Pursuant to Rule 416(a) under the Securities Act, the Registration Statements are also amended to cover any additional shares of Common Stock which may be issued under the applicable equity-based compensation plans to prevent dilution resulting from any subsequent stock splits, stock dividends or similar transactions. The contents of the Registration Statements are hereby incorporated by reference pursuant to General Instruction E on Form S-8. PART I INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS 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 INFORMATION REQUIRED IN THE REGISTRATION STATEMENT Item 3. Incorporation of Documents by Reference. Not required to be filed with this Registration Statement pursuant to General Instruction E on Form S-8. Item 4. Description of Securities. Not required to be filed with this Registration Statement pursuant to General Instruction E on Form S-8. Item 5. Interests of Named Experts and Counsel. Not required to be filed with this Registration Statement pursuant to General Instruction E on Form S-8.

Item 6. Indemnification of Directors and Officers. Not required to be filed with this Registration Statement pursuant to General Instruction E on Form S-8. Item 7. Exemption from Registration Claimed. Not applicable. Item 8. Exhibits. Exhibit No. Description Filed Herewith or Incorporated by Reference 4.1 Specimen Common Stock Certificate Incorporated by reference to Form 10-Q for the fiscal quarter ended June 30, 2000, at Exhibit 4(a) 4.2 Specimen Rights Certificate Incorporated by reference to Current Report on Form 8-K dated February 3, 2000, at Exhibit B to Exhibit 4.1 4.3 Rights Agreement dated as of Incorporated by reference to Current September 24, 1990 (as amended Report on Form 8-K dated February 3, and restated as of February 3, 2000, at Exhibit 4.1 2000) between the Registrant and Registrar and Transfer Company, as successor Rights Agent 4.4 Credit Agreement dated as of Incorporated by reference to Form 10-K October 6, 2004, among the for the fiscal year ended September 30, Registrant, Wells Fargo Bank, 2004, at Exhibit 4.4 N.A., as agent, and the lenders listed therein 5 Opinion of Counsel 23.1 Consent of Counsel (included in Exhibit 5) 23.2 Consent of KPMG LLP 24 Power of Attorney (included on the Signatures pages of the Registration Statements)

Item 9.Undertakings Not required to be filed with this Registration Statement pursuant to General Instruction E on Form S-8. 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 city of Ladue, state of Missouri, on this 20th day of September, 2005. ESCO TECHNOLOGIES INC. By: /s/ T.B. Martin ---------------- T.B. Martin Assistant Secretary and Associate General Counsel 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 date indicated. Signature Title Date /s/ * Chairman, Chief Executive Officer and September 20, 2005 - ---------------- Director (principal executive officer) V. L. Richey, Jr. /s/ * President, Chief Operating Officer and September 20, 2005 - ---------------- Director C. J. Kretschmer /s/ * Vice President and Chief Financial September 20, 2005 - -------------- Officer (principal financial and G. E. Muenster accounting officer) /s/ * Director September 20, 2005 - --------------- W. S. Antle III /s/ * Director September 20, 2005 - --------------- J. M. McConnell /s/ * Director September 20, 2005 - ------------ L. W. Solley /s/ * Director September 20, 2005 - ------------- J. M. Stolze /s/ * Director September 20, 200 - -------------- D. C. Trauscht /s/ * Director September 20, 2005 - ------------ J. D. Woods */s/T.B. Martin September 20, 2005 - --------------- T.B. Martin Assistant Secretary and Associate General Counsel By power of attorney

EXHIBIT INDEX Exhibits are listed by number corresponding to the Exhibit Table of Item 601 in Regulation S-K. 5 Opinion of Counsel. 23.1 Consent of Counsel (included in Exhibit 5) 23.2 Consent of KPMG LLP. 24 Power of Attorney (included on the Signatures pages of the Registration Statements) See Item 8 for a list of exhibits incorporated by reference.

                                                                       EXHIBIT 5


                                       September 20, 2005




ESCO Technologies Inc.
9900A Clayton Road
St. Louis, MO  63124-1186

Ladies and Gentlemen:

     I am Assistant Secretary and Associate General Counsel of ESCO Technologies
Inc., a Missouri corporation (the "Company"), and in such capacity I am familiar
with the  Post-Effective  Amendment No. 1 to the Registration  Statement on Form
S-8 (the  "Post-Effective  Amendment")  relating  to the  Company's  2001  Stock
Incentive Plan and 2004 Incentive  Compensation Plan (the "Plans") to which this
letter is filed as an exhibit. The Post-Effective  Amendment registers 2,105,365
shares of the  Company's  common  stock,  par value $0.01 per share (the "Common
Stock"),   offered  pursuant  to  stock  options,   stock  appreciation  rights,
performance share awards,  restricted stock awards and other stock-based awards,
granted and which may be granted under the Plans,  including the Preferred Stock
Purchase  Rights  associated  with such Common  Stock (the Common  Stock and its
associated Preferred Stock Purchase Rights, the "Securities").

     I have examined originals or copies,  certified or otherwise  identified to
my satisfaction,  of such documents,  corporate records,  certificates of public
officials  and other  instruments  as I deemed  necessary for the purpose of the
opinion expressed herein.

     On the basis of the  foregoing,  I am of the opinion  that the  Securities,
when sold or distributed in accordance with the provisions of the Plans, will be
legally issued, fully paid and non-assessable.

     I consent to the filing of this letter as an exhibit to the  Post-Effective
Amendment.

                                                    Very truly yours,


                                                    /s/ Thomas B. Martin_____
                                                    Thomas B. Martin

TBM/bjo

Enclosures


                                                                 EXHIBIT 23.2








            Consent of Independent Registered Public Accounting Firm



The Board of Directors
ESCO Technologies Inc.:

We consent to the use of our reports dated  November 9, 2004 with respect to the
consolidated  balance sheets of ESCO  Technologies Inc. as of September 30, 2004
and 2003, and the related consolidated  statements of operations,  shareholders'
equity,  and cash  flows for each of the years in the  three-year  period  ended
September  30, 2004,  and related  financial  statement  schedule,  incorporated
herein by  reference  in this  post-effective  amendment  No. 1 to  registration
statement on Form S-8 of ESCO Technologies Inc.

Our reports refer to a change in accounting  for the  consolidation  of variable
interest entities on July 1, 2003.


/s/ KPMG LLP
    KPMG LLP

St. Louis, Missouri
September 21, 2005