<PAGE>
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 F O R M 10-K/A
                               (Amendment No. 1)

[X]      ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934 [NO FEE REQUIRED]

         For the fiscal year ended December 29, 2001

         Commission File Number 1-313

[ ]      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934 [NO FEE REQUIRED]

                            THE LAMSON & SESSIONS CO.
                 (Exact name of Registrant as specified in its charter)

                  Ohio                                  34-0349210
                  ----                                  ----------
     (State or other jurisdiction of          (IRS Employer Identification No.)
     incorporation or organization)
        25701 Science Park Drive
             Cleveland, Ohio                            44122-7313
             ---------------                            ----------
 (Address of principal executive offices)               (Zip Code)

        Registrant's telephone number, including area code: 216/464-3400

           SECURITIES REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT:

                                                NAME OF EACH EXCHANGE
             TITLE OF EACH CLASS                 ON WHICH REGISTERED
             -------------------                 -------------------
       Common Shares, without par value        New York Stock Exchange
                                               Pacific Stock Exchange

        Securities registered pursuant to Section 12(g) of the Act: None

         Indicate by check mark whether the Registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes [X] No [ ]

         Indicate by check mark if disclosure of delinquent filers pursuant to
Item 405 of Regulation S-K is not contained herein, and will not be contained,
to the best of Registrant's knowledge, in definitive proxy or information
statements incorporated by reference in Part III of this Form 10-K or any
amendment to this Form 10-K. [ ]

         The aggregate market value of the voting stock held as of February 8,
2002 by non-affiliates of the Registrant: $52,801,571.

         As of February 8, 2002 the Registrant had outstanding 13,777,608 common
shares.

                       DOCUMENTS INCORPORATED BY REFERENCE

         Portions of the Proxy Statement for the 2002 Annual Meeting of
Shareholders are incorporated by reference into Part III.


<PAGE>
Operating expenses were $54.1 million in 2000 ($6.1 million higher than 1999),
or 15.5%, of net sales compared with 16.5% of net sales in 1999. Continued
productivity improvements in general administrative activities offset increases
in sales commission and legal, professional and acquisition related expenses.
The result was more than a two-and-a-half times increase in operating income to
$34.5 million (9.9% of net sales) in 2000 versus $13.3 million (4.6% of net
sales) in 1999.

Interest expense increased by $7 million in 2001 due to the acquisition debt of
approximately $113 million added late in 2000. The Company had an average
borrowing rate during 2001 of 6.81% compared with 7.85% in 2000.

The Company's earnings before interest, taxes, depreciation and amortization
(EBITDA) was $24.2 million for 2001, compared with the $45.7 million EBITDA
earned in 2000.

FINANCIAL CONDITION
Despite the lower operating income in 2001, the Company focused on generating
cash flow from working capital reductions. Working capital was $31.2 million at
the end of 2001 compared with $58.3 million at the end of 2000. The current
ratio decreased to 1.50 in 2001 from 1.76 in 2000 as accounts receivable and
inventory declined by a combined $34.9 million from lower economic activity and
improved inventory control, while payables and accruals declined by $17.7
million. Cash flow generated from operating activities was a strong $30.1
million in 2001 versus $27.5 million in 2000.

Accounts receivable were $39.2 million at the end of 2001, compared with $56.6
million at the end of 2000. Days sales outstanding in 2001 were about 49.5 and
approximately the same as the 50.8 days for 2000.

Inventory levels at the end of 2001 were $42.1 million compared with $59.6
million at the end of 2000. As a result, annual inventory turns increased from
3.9 times in 2000 to 4.9 times in 2001. All inventory categories have been
reduced. However, the largest reduction came in PVC resin and related products
for which pounds in inventory were lower and average unit cost at year-end was
more than 30% below the 2000 year-end levels.

Accounts payable decreased by $6.6 million in 2001 from the prior year-end,
primarily from the purchasing of raw material inventory and lower unit costs for
these items.

The current balance in deferred tax assets decreased due to lower than expected
2002 operating results limiting the short term utilization of net operating
losses. Accrued liabilities at 2001 year-end were approximately $11 million less
than the prior year, as the final purchase price adjustment for Ameriduct was
paid in 2001; incentive compensation is lower in the current year; and legal and
environmental liabilities have been adjusted to reflect current evaluations of
these items. The current portion of long-term debt has increased to reflect the
amortization schedule of term debt provided in our credit agreement. The strong
operating cash flow experienced in the fourth quarter of the year allowed the
Company to pay down debt by over $22 million during 2001, a 15.9% reduction.

Capital expenditures totaled approximately $8.0 million in 2001, compared with
$11.1 million in 2000. The current year spending was primarily for distribution
center productivity, new product tooling and quality enhancements.

The Company has adequate credit capacity available to support its current
operational expense and capital spending needs as well as those anticipated for
the remainder of 2002. However, the Company has been experiencing lower earnings
levels in its PVC Pipe business, reflecting an oversupply of raw material
available to support existing market demand as well as extremely low demand
levels in the telecommunications infrastructure market, which is expected to
continue through 2002. Unless the EBITDA level improves sufficiently, the
Company will seek a further amendment to its secured credit agreement in order
to prevent a covenant violation and, concurrently, evaluate changes to its
capital structure in order to ensure an appropriate degree of financial
flexibility. The Company has commenced negotiations of such an amendment so that
it can be entered into before a covenant violation occurs.

OUTLOOK
The following paragraphs contain forward-looking comments. The comments are
subject to, and the actual future results may be impacted by, the cautionary
limitations and factors outlined in the following narrative comments.




                                       10
<PAGE>



NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--CONTINUED
THE LAMSON & SESSIONS CO. AND SUBSIDIARIES
NOTE C--LONG-TERM DEBT AND COMMITMENTS--CONTINUED

In August 2000, the Company completed the refinancing of its previous secured
credit agreement by entering into a new five-year, $125 million revolving
credit agreement with a consortium of banks led by Harris Trust of Chicago. In
December 2000, in conjunction with the acquisition of Ameriduct, the agreement
was amended and increased to a $194 million facility, consisting of $48.5
million in term debt and $145.5 million in a revolver. As of September 30, 2001
the agreement was amended reducing the credit commitments of the lenders to
an aggregate $170 million of which $38.5 million is available for the issuance
of letters of credit. Beginning in the third quarter of 2001, the term portion
of this agreement requires principal payments of $2 million on March 31 and
June 30 and $3.5 million on September 30 and December 31 of each year with a
balloon payment in August 2005. This agreement is secured by substantially all
of the Company's assets. Interest on this credit facility is at LIBOR plus 1.5%
to 3.5%. The specific rate is determined based on the ratio of indebtedness to
earnings before interest, taxes, depreciation and amortization and is adjusted
quarterly. The rate at December 29, 2001 is 7.24%. In addition to amounts
borrowed, letters of credit related to Industrial Revenue Bond financings and
other contractual obligations total approximately $15.8 million under the
agreement. The Company's credit agreement contains various restrictive
covenants pertaining to maintenance of net worth, certain financial ratios and
limits the amount of stock repurchases and dividend payments.

The Company's Industrial Revenue Bond financings include several issues due in
annual installments from 2000 through 2023 with interest at variable rates. The
weighted average rate for these bonds at December 29, 2001 was 1.78%.

The Company's headquarters is subject to a mortgage payable in equal monthly
installments through 2003 with interest at 8.625%.

The aggregate minimum combined maturities of long-term debt for the years 2003
through 2006 are approximately $12,070,811, $11,660,000, $72,760,000 and
$665,000 respectively, with $7,110,000 due thereafter.

Interest paid was $9,573,000, $4,026,000 and $3,679,000 in 2001, 2000 and 1999,
respectively.

Rental expense was $6,268,000, $5,861,000 and $4,908,000 in 2001, 2000 and 1999,
respectively. Aggregate future minimum payments related to non-cancelable
operating leases with initial or remaining terms of one year or more for the
years 2002 through 2006 are approximately $3,637,000, $3,129,000, $2,699,000,
$1,964,000 and $1,578,000, respectively, with $5,139,000 due thereafter.

NOTE D--DERIVATIVES AND HEDGING

Effective as of December 31, 2000, the Company adopted Statement of Financial
Accounting Standards No. (SFAS) 133, "Accounting for Derivative Instruments and
Hedging Activities" which was issued in June, 1998 by the Financial Accounting
Standards Board (FASB), as amended by SFAS 137, "Accounting for Derivative
Instruments and Hedging Activities - Deferral of Effective Date of SFAS 133" and
SFAS 138, "Accounting for Certain Derivative Instruments and Certain Hedging
Activities."

As a result of the adoption of SFAS 133, the Company is required to recognize
all derivative financial instruments as either assets or liabilities at fair
value. Derivative instruments that are not hedges must be adjusted to fair value
through net income. Under the provisions of SFAS 133, changes in the fair value
of derivative instruments that are classified as fair value hedges are offset
against changes in the fair value of the hedged assets, liabilities, or firm
commitments, through net income. Changes in the fair value of derivative
instruments that are classified as cash flow hedges are recognized in other
comprehensive income until such time as the hedged items are recognized in net
income.





                                       20
<PAGE>




NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--CONTINUED
THE LAMSON & SESSIONS CO. AND SUBSIDIARIES
NOTE I--STOCK COMPENSATION PLANS--CONTINUED

The following table summarizes information about options outstanding at December
29, 2001:
<TABLE>
<CAPTION>

                                            OPTIONS OUTSTANDING                                      OPTIONS EXERCISABLE
                           ---------------------------------------------------------          --------------------------------
                                             WEIGHTED-AVERAGE
       RANGE OF              SHARES               REMAINING          WEIGHTED-AVERAGE           SHARES        WEIGHTED-AVERAGE
   EXERCISE PRICES         AT 12/29/01       CONTRACTUAL LIFE (YRS)   EXERCISE PRICE          AT 12/29/01       EXERCISE PRICE
   ---------------         -----------       ----------------------   --------------          -----------       --------------

<S>                           <C>                   <C>                  <C>                <C>                 <C>
            $ 0-5               265,250               7.07                 $ 4.97               197,250             $ 4.97
             5-10             1,718,550               5.72                   7.39             1,188,683               6.86
            10-15                38,500               7.70                  10.88                20,667              10.65
            15-20                10,000               8.65                  17.94                 3,333              17.94

</TABLE>


The Company applies Accounting Principles Board Opinion No. 25 "Accounting for
Stock Issued to Employees" and related interpretations in accounting for its
stock-based plans. Accordingly, compensation cost has not been recognized for
the fixed stock-based compensation plans. Had compensation expense been
recognized following SFAS No. 123, "Accounting for Stock-Based Compensation,"
the Company's pro forma net income and earnings per share would have been as
follows:
<TABLE>
<CAPTION>


                                                                                                  FISCAL YEARS
                                                                      ------------------------------------------------------------
(Dollars in thousands, except per share data)                             2001                2000                      1999
                                                                      ------------------------------------------------------------

<S>                                       <C>                         <C>                   <C>                        <C>
Net income                                As reported                 $ (3,843)             $ 21,448                   $ 18,788
                                          Pro forma                     (4,507)               20,941                     18,322

Basic earnings per share                  As reported                  $ (0.28)               $ 1.58                     $ 1.40
                                          Pro forma                      (0.33)                 1.54                       1.36

Diluted earnings per share                As reported                  $ (0.28)               $ 1.53                     $ 1.39
                                          Pro forma                      (0.33)                 1.50                       1.36

</TABLE>


For pro forma calculations, the fair value of each stock option grant is
estimated on the date of grant using the Black-Scholes option-pricing model with
the following weighted-average assumptions used for grants:
<TABLE>
<CAPTION>

                                                2001                     2000                    1999
                                           ------------------------------------------------------------
<S>                                          <C>                     <C>                     <C>
Expected volatility                             57.2%                   52.2%                   29.8%

Risk-free interest rates                        4.87%                   6.05%                   5.74%

Average expected life                         5 years                 5 years                 5 years
</TABLE>


The Company has deferred compensation plans that provide both certain executive
officers and directors of the Company with the opportunity to defer receipt of
executive bonus compensation and director fees, respectively. The Company
funds these deferred compensation liabilities by making contributions to the
Rabbi Trusts which invest exclusively in the Company's common shares. In
accordance with Emerging Issues Task Force (EITF) 97-14 "Accounting for
Deferred Compensation Arrangements Where Amounts Earned Are Held in a Rabbi
Trust and Invested," both the trust assets and the related obligation are
recorded in equity at cost and offset each other.


                                       26

<PAGE>



NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--CONTINUED
THE LAMSON & SESSIONS CO. AND SUBSIDIARIES

NOTE L--BUSINESS SEGMENTS--CONTINUED
<TABLE>
<CAPTION>

(Dollars in thousands)                                                         2001               2000               1999
                                                                            ---------          ---------          ---------

<S>                                                                         <C>                <C>                <C>
NET SALES
Carlon                                                                      $ 188,161          $ 142,979          $ 120,975
Lamson Home Products                                                           62,128             63,351             53,401
PVC Pipe                                                                      102,383            142,403            117,005
                                                                            ---------          ---------          ---------

                                                                            $ 352,672          $ 348,733          $ 291,381
                                                                            =========          =========          =========

OPERATING INCOME (LOSS)
Carlon                                                                      $  14,585          $  21,687          $  15,065
Lamson Home Products                                                            3,724              1,856              1,135
PVC Pipe                                                                      (11,220)            20,224              5,814
Corporate Office                                                                 (906)            (9,280)            (8,668)
                                                                            ---------          ---------          ---------

                                                                            $   6,183          $  34,487          $  13,346
                                                                            =========          =========          =========

DEPRECIATION AND AMORTIZATION
Carlon                                                                      $  12,080          $   5,187          $   3,737
Lamson Home Products                                                            2,508              2,520              2,792
PVC Pipe                                                                        3,431              3,522              3,607
                                                                            ---------          ---------          ---------

                                                                            $  18,019          $  11,229          $  10,136
                                                                            =========          =========          =========

IDENTIFIABLE ASSETS
Carlon                                                                      $ 153,194          $ 184,527          $  52,326
Lamson Home Products                                                           28,157             31,720             30,658
PVC Pipe                                                                       45,684             61,449             51,393
Corporate Office (includes deferred tax and pension assets)                    46,786             42,597             48,942
                                                                            ---------          ---------          ---------

                                                                            $ 273,821          $ 320,293          $ 183,319
                                                                            =========          =========          =========

</TABLE>


Substantially all sales are made within North America. Net sales to a single
customer within the Carlon and PVC Pipe segments totaled approximately 14% in
2001, and 17% in 2000 and 1999 of consolidated net sales.


<TABLE>
<CAPTION>

                                                                                                                 2001 OPERATING
                                                                               2001                NET            INCOME (LOSS)
                                                                            OPERATING             CHARGE         EXCLUDING NET
                                                                          INCOME (LOSS)           (GAIN)         CHARGE (GAINS)
                                                                          -------------        -----------       -------------

<S>                                                                         <C>                <C>                <C>
Carlon                                                                      $  14,585          $   3,762          $  18,347
Lamson Home Products                                                            3,724              1,149              4,873
PVC Pipe                                                                      (11,220)               661            (10,559)
Corporate Office                                                                 (906)            (2,400)            (3,306)
                                                                            ---------          ---------          ---------

                                                                            $   6,183          $   3,172          $   9,355
                                                                            =========          =========          =========
</TABLE>


The above schedule shows the operating results by segment excluding the
restructuring and impairment charge of $7.7 million and net gains of $4.6
million recorded in 2001.



                                       30

<PAGE>



SIGNATURES


Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange
Act of 1934, the Registrant has duly caused this report to be signed on its
behalf by the undersigned, thereunto duly authorized, on this March 5, 2002.


                  THE LAMSON & SESSIONS CO.


             By   /s/ James J. Abel
                  -----------------------------------
                  James J. Abel
                  Executive Vice President, Secretary,
                  Treasurer and Chief Financial Officer


Pursuant to the requirements of the Securities Exchange Act of 1934, this report
has been signed below by the following persons on behalf of the Registrant and
in the capacities indicated as of February 20, 2002.


             Signature                               Title
             ---------                               -----


/s/ John B. Schulze                     Chairman of the Board, President
----------------------------            and Chief Executive Officer
John B. Schulze                         (Principal Executive Officer)



/s/ James J. Abel                       Executive Vice President, Secretary,
----------------------------            Treasurer and Chief Financial Officer
James J. Abel                           (Principal Financial Officer)



/s/ Lori L. Spencer                     Vice President and Controller
----------------------------            (Principal Accounting Officer)
Lori L. Spencer


/s/ James T. Bartlett*                  Director
----------------------------
James T. Bartlett



/s/ Francis H. Beam, Jr.*               Director
-------------------------
Francis H. Beam, Jr.



/s/ Martin J. Cleary*                   Director
-------------------------
Martin J. Cleary




                                       38
<PAGE>




/s/ William H. Coquillette*             Director
---------------------------
William H. Coquillette


/s/ John C. Dannemiller*                Director
-------------------------
John C. Dannemiller


/s/ George R. Hill*                     Director
-------------------------
George R. Hill


/s/ A. Malachi Mixon, III*              Director
--------------------------
A. Malachi Mixon, III


/s/ John C. Morley*                     Director
------------------------
John C. Morley


/s/ D. Van Skilling*                    Director
-------------------------
D. Van Skilling


     *       The undersigned, by signing his name hereto, does sign and execute
             this Annual Report on Form 10-K pursuant to a Power of Attorney
             executed on behalf of the above-named directors of The Lamson &
             Sessions Co. and filed herewith as Exhibit 24 on behalf of The
             Lamson & Sessions Co. and each such person.




             March  5, 2002



By /s/ James J. Abel
   ----------------------------------------
     James J. Abel, Attorney-in-fact







                                       39