<PAGE>   1





                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549

                                   FORM 10-K
(Mark One)
[X]      ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
         EXCHANGE ACT OF 1934 (Fee Required)
                  For the fiscal year ended December 31, 1996.
                                       OR
[  ]     TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
         EXCHANGE ACT OF 1934 (No Fee Required)

            For the transition period from __________ to __________

                         Commission File Number 0-10849

                           SOUTHSIDE BANCSHARES CORP.
            --------------------------------------------------------
             (Exact Name of Registrant as Specified in Its Charter)

<TABLE>
<S><C>
             MISSOURI                                                                    43-1262037
----------------------------------------                                  ---------------------------------------------
(State or Other Jurisdiction of Incorporation or Organization)                  (I.R.S. Employer Identification No.)

  3606 GRAVOIS AVENUE, ST. LOUIS, MISSOURI                                        63116
-----------------------------------------------------------------------------------------------------------------------
(Address of Principal Executive Offices)                                        (Zip Code)
</TABLE>

Registrant's Telephone Number, Including Area Code:    (314) 776-7000
                                                     ------------------------

          Securities registered pursuant to Section 12(b) of the Act:

                                                  Name of Each Exchange
               Title of Each Class                 on Which Registered
               -------------------                ----------------------
                     NONE                                    NONE

          Securities registered pursuant to Section 12(g) of the Act:

                         COMMON STOCK, $1.00 PAR VALUE
                                (Title of Class)

                      ------------------------------------

         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 the Registrant's knowledge, in definitive proxy or information
statements incorporated by references in Part III of this Form 10-K or any
amendment to this Form 10-K. [  ]

         At March 17, 1997, the aggregate market value, computed by the average
bid and asked prices, of the voting stock held by non-affiliates of the
Registrant was approximately $73,727,420.00.

         At March 17, 1997, the number of shares outstanding of the
Registrant's common stock, $1.00 par value, was 2,835,670.

                      DOCUMENTS INCORPORATED BY REFERENCE
(1)      Portions of the Registrant's Annual Report to Shareholders for the
         fiscal year ended December 31, 1996 (Part I and Part II); and

(2)      Portions of the Registrant's Proxy Statement for the Annual Meeting of
         Shareholders scheduled for April 24, 1997 (Part III).
================================================================================
<PAGE>   2

                                     PART I

ITEM 1.  BUSINESS

         (a)     General

         Southside Bancshares Corp. (the "Registrant" or "Southside") was
incorporated under the laws of the State of Missouri on January 25, 1982.
Southside became a registered bank holding company on January 3, 1983, when
South Side National Bank in St. Louis and a wholly-owned subsidiary of the
Registrant were merged on that date.  The wholly-owned subsidiary of the
Registrant now continues banking operations under the name "South Side National
Bank in St. Louis."  Prior to such merger, the Registrant was not actively
involved in any banking operations.  Southside's principal office is located at
3606 Gravois Avenue, St. Louis, Missouri 63116.

         Southside, through its subsidiary banks, is primarily engaged in
commercial banking and providing trust services.  The Registrant and its
subsidiaries had, at December 31, 1996, consolidated total assets of
approximately $528 million.  The following table shows the year of acquisition,
total assets, total loans and total deposits at December 31, 1996, of each of
Southside's wholly-owned subsidiary banks, all of which are located in
Missouri.

<TABLE>
<CAPTION>
                                                                                    (in thousands)
                                  Year of              --------------------------------------------------------------------------
            Bank                Acquisition             Total Assets                 Total Loans            Total Deposits
            ----                -----------             ------------                 -----------            --------------
<S>                                  <C>                   <C>                         <C>                     <C>
South Side National Bank
  in St. Louis                       1983                  $338,077                    $172,877                $299,586
State Bank of DeSoto                 1983                  $ 54,340                    $ 38,049                $ 48,449
Bank of Ste. Genevieve               1985                  $ 89,490                    $ 51,686                $ 79,897
The Bank of St. Charles
  County                             1986                  $ 44,286                    $ 31,851                $ 39,732
</TABLE>


         The Registrant's subsidiary banks, which operated 13 banking offices
in Missouri during 1996, are engaged in the general banking business of
accepting funds for deposit, making loans, renting safe deposit boxes and
performing such other banking services as are usual and customary in banks of
similar size and character.  All of the subsidiary banks offer real estate,
commercial and consumer loans. Customers of all subsidiary banks are offered
regular checking, interest-bearing checking, money market, savings,
certificates of deposit and IRA accounts.  South Side National Bank in St.
Louis ("SSNB"), State Bank of DeSoto and The Bank of St. Charles County also
provide BankMate and CIRRUS 24-hour automated teller machines.  Bank of Ste.
Genevieve has a 24-hour banking machine on the Shazam and Plus automated teller
networks at its Plaza Bank location.  SSNB also provides a 24-hour automated
teller machine (ATM) at its Customer-Bank Communications Terminal branch in St.
Anthony's Medical Center located at 10010 Kennerly Road, St. Louis County,
Missouri 63128.

         Customers of all of the subsidiary banks are also offered the services
of the trust department of SSNB.  At December 31, 1996, the combined market
value of fiduciary and custodial assets under management of the trust
department was approximately $276 million, which are not included in the
consolidated assets of the Registrant as they do not represent assets of the
Registrant.

         The responsibility for the management of the subsidiary banks remains
with the officers and directors of the respective banks.  Southside provides
the subsidiary banks with assistance and service in auditing, record keeping,
tax planning, trust operations, new business development, lending, regulatory
compliance and human resources management.

         Southside has nine officers.  Southside utilizes, to the extent
necessary, the officers, employees and services of its banking subsidiaries.
The total number of full and part-time employees of the Registrant and its
wholly-owned subsidiaries was 217 and 34, respectively, on December 31, 1996.

         The information on page 4 of the Southside Bancshares Corp. 1996
Annual Report is incorporated herein by reference.

<PAGE>   3

         (b)     Supervision and Regulation

         Southside is a bank holding company within the meaning of the Bank
Holding Company Act of 1956, as amended (the "BHCA"), and, as such, is subject
to regulation, supervision and examination by the Board of Governors of the
Federal Reserve System (the "Federal Reserve Board").  Registered bank holding
companies are required to file an annual report with the Federal Reserve Board
and to provide the Federal Reserve Board with such additional information as
the Federal Reserve Board may require pursuant to the BHCA.

         The BHCA requires that bank holding companies obtain prior approval
from the Federal Reserve Board before (1) acquiring (except in certain limited
circumstances) direct or indirect ownership or control of more than 5% of the
voting shares of any bank or bank holding company, (2) acquiring all or
substantially all of the assets of any bank or bank holding company, or (3)
merging or consolidating with any other bank holding company.  In determining
whether to approve a proposed acquisition, merger or consolidation, the Federal
Reserve Board is required to take into consideration the financial and
managerial resources and future prospects of the company or companies and the
banks concerned, and the convenience and needs of the community to be served.

         The BHCA also prohibits any bank holding company, or any subsidiary
thereof, from acquiring, directly or indirectly, more than 5% of the voting
shares of, interest in, or all or substantially all of the assets of any
additional bank located outside the state in which the operations of such bank
holding company's banking subsidiaries were principally conducted on the date
which such company became a bank holding company unless the acquisition of such
shares or assets of a state bank by an out-of-state bank holding company is
specifically authorized by the statutes of the state in which the bank is
located.  Missouri law  permits banks and bank holding companies in states
contiguous to Missouri to acquire banks and bank holding companies located in
Missouri, if such states have passed reciprocal interstate banking laws.  A
bank or bank holding company having its principal operations in Iowa, Illinois,
Kentucky, Tennessee, Arkansas, Oklahoma, Kansas or Nebraska is currently
permitted to acquire control of Missouri banks since all of the states listed
above have adopted regional or national interstate banking legislation
reciprocal with that of Missouri.

         Missouri law provides that a bank holding company may not obtain
control of any bank if as a result of the acquisition, the total deposits in
such bank together with the total deposits of all banks located in the State of
Missouri controlled by the bank holding company would exceed 13% of the total
deposits of all depository financial institutions in the state, including
banks, thrifts and credit unions.  In computing the total deposits in all banks
controlled by the bank holding company and the bank which the holding company
seeks to acquire, certificates of deposit in the face amount of $100,000 or
more, deposits from sources outside the United States and deposits of banks
other than banks controlled by the bank holding company are to be deducted.

         The BHCA further prohibits a bank holding company, with certain
exceptions, from engaging in and from acquiring direct or indirect ownership or
control of more than 5% of the voting shares of any company engaged in a
business other than that of banking, managing and controlling banks, or
furnishing services to its affiliated banks.  An exception to this prohibition
provides that a bank holding company may engage in, and may own shares of
companies engaged in, certain businesses which the Federal Reserve Board has
determined to be so closely related to banking as to be a proper incident
thereto.  The Federal Reserve Board has adopted regulations specifying areas of
activity which it regards as so closely related to banking or the managing of
banks as to be permissible for bank holding companies under the law, subject to
Board approval in individual cases.  The Registrant is not engaged in any such
non-banking activities.

         In September 1994, the Riegle-Neal Interstate Banking and Branching
Efficiency Act of 1994 was enacted.  As of September 29, 1995, bank holding
companies have the right to expand, by acquiring existing banks, into all
states, even those which had theretofore restricted entry, subject to state
deposit caps and a 10% nationwide deposit cap.  This legislation also provides
that, subject to future action by individual states, a holding company has the
right, commencing on June 1, 1997, to convert the banks which it owns in
different states to branches of a single bank.  States are permitted to "opt
out" of this full interstate branching provision prior to the effective date,
but may not "opt out" of the law allowing bank holding companies from other
states to enter such states.  Alternatively, states may "opt in" earlier than
June 1, 1997.  As of the date hereof, the state of Missouri, in which all of
the Registrant's subsidiary banks are located, has neither "opted in" nor
"opted out" of the interstate branching provisions of this legislation.





                                       2
<PAGE>   4


         Subsidiary banks of a bank holding company are subject to certain
restrictions imposed by the Federal Reserve Act on any extensions of credit to
the bank holding company or any of its other subsidiaries, on investments in
the stock or other securities thereof, and on the taking of such stock or
securities as collateral for loans to any borrower.  Further, under the BHCA
and regulations of the Federal Reserve Board, a bank holding company and its
subsidiaries are prohibited from engaging in certain tie-in arrangements in
connection with any extension of credit, lease or sale of property, or
furnishing of services.

         The primary subsidiary of the Registrant, South Side National Bank in
St. Louis, is a national bank and, as such, its primary bank regulatory
authority is the Office of the Comptroller of the Currency.  A national bank is
also regulated by the Federal Reserve Board and the Federal Deposit Insurance
Corporation.  Banks organized under state law which are members of the Federal
Reserve System are regulated and examined primarily by the Federal Reserve
Board and state banking authorities, while banks organized under state law
which are not members of the Federal Reserve System are regulated and examined
primarily by the Federal Deposit Insurance Corporation and state banking
authorities.  The Bank of Ste. Genevieve is a state-chartered bank which is a
member of the Federal Reserve System, while State Bank of DeSoto and The Bank
of St. Charles County are state-chartered banks which are not members of the
Federal Reserve System.  Regulation by the federal and state banking
authorities is designed to protect depositors rather than shareholders.

         Subsidiary bank dividends are the principal source of revenue to the
Registrant although management fees may be charged to cover services rendered
to such subsidiary banks.  The ability of each subsidiary bank to pay such
dividends to Southside is subject to limitations established by various state
and federal laws and regulations. Banks organized under either federal or state
laws are limited in the amount of dividends they may declare, depending upon
the amount of their capital and surplus, and in certain instances must obtain
regulatory approval before declaring dividends.  Under the National Banking
Act, until a national bank's surplus equals or exceeds the amount of its
capital, no dividend may be declared unless at least one-tenth of the national
bank's net profit earned since declaration of the last dividend has been
transferred to surplus.  Under federal law, regulatory approval is required for
any dividend by a national bank or a state-chartered bank which is a member of
the Federal Reserve System if the total of all dividends declared by the bank
in any calendar year would exceed the total of its net income for that year
combined with its retained net income for the preceding two years, less any
required transfers to surplus.  Under Missouri law, a state-chartered bank
which is not a member of the Federal Reserve System whose surplus account for
each dividend period does not equal at least 40% of the amount of its capital
stock is required to transfer to its surplus account 10% of its net income for
such dividend period.  Retained earnings in excess of any such required
transfer to surplus are available for dividends.  In addition, sound banking
practices require the maintenance of adequate levels of capital.  Federal
regulatory authorities have adopted standards for the maintenance of capital by
banks, and adherence to such standards may further limit the ability of banks
to pay dividends.

         The Federal Deposit Insurance Corporation Improvement Act of 1991
("FDICIA"), among other things, identifies the following capital standards for
depository institutions:  well capitalized, adequately capitalized,
undercapitalized, significantly undercapitalized and critically
undercapitalized.  A depository institution is well capitalized if it
significantly exceeds the minimum level required by regulation for each
relevant capital measure, adequately capitalized if it meets each such measure,
undercapitalized if it fails to meet any such measure, significantly
undercapitalized if it is significantly below any such measure, and critically
undercapitalized if it fails to meet any critical capital level set forth in
the regulations.  FDICIA requires a bank that is determined to be
undercapitalized to submit a capital restoration plan, and the bank's holding
company must guarantee that the bank will meet its capital plan, subject to
certain limitations.  FDICIA also prohibits banks from making any capital
distribution or paying any management fee if the bank would thereafter be
undercapitalized.

         FDICIA grants the FDIC authority to impose special assessments on
insured depository institutions to repay FDIC borrowings from the United States
Treasury or other sources and to establish semiannual assessment rates on Bank
Insurance Fund ("BIF") member banks so as to maintain the BIF at the designated
reserve ratio defined in FDICIA.  FDICIA also required the FDIC to implement a
risk-based insurance assessment system pursuant to which the premiums paid by a
depository institution are based on the probability that the BIF will incur a
loss in respect of such institution.  The FDIC has adopted a deposit insurance
assessment system that places each insured institution in one of nine risk
categories based on the level of its capital, evaluation of its risks by its
primary state or federal supervisor, statistical analysis and other
information.  The FDIC has recently adopted an amendment to the BIF risk-based
assessment schedule which effectively eliminated deposit insurance assessments
for most commercial banks and other depository institutions with deposits
insured by the BIF.  Under the FDIC amendment, the





                                       3
<PAGE>   5

assessment rates for BIF-insured institutions range from 0.27% of insured
deposits for the most financially troubled BIF members to 0% of deposits for
most well-capitalized institutions, including over 90% of BIF-insured
institutions.

         The Economic Growth and Regulatory Paperwork Reduction Act of 1996
("EGRPRA") was signed into law on September 30, 1996.  EGRPRA streamlined the
non-banking activities application process for well-capitalized and
well-managed bank holding companies.  Under EGRPRA, qualified bank holding
companies may commence a regulatory approved non-banking activity without prior
notice to the Federal Reserve Board.  Written notice is required within 10 days
after commencing the activity.  Under EGRPRA, the prior notice period is
reduced to 12 days in the event of any non-banking acquisition or share
purchase, assuming the size of the acquisition does not exceed 10% of
risk-weighted assets of the acquiring bank holding company and the
consideration does not exceed 15% of Tier I capital.  The foregoing prior
notice requirement also applies to commencing non-banking activity de novo
which has been previously approved by order of the Federal Reserve Board, but
not yet implemented by regulations.  EGRPRA also provides for the
recapitalization of the Savings Association Insurance Fund in order to bring
that fund into parity with the BIF of the FDIC.

         The references in this section to various aspects of supervision and
regulation are brief summaries which do not purport to be complete and which
are qualified in their entirety by reference to applicable laws, rules and
regulations.  Any change in applicable laws or regulations may have a material
effect on the business and prospects of Southside.  The operations of Southside
may be affected by legislative changes and by the policies of various
regulatory authorities.  Southside is unable to predict the nature or the
extent of the effects on its business and earnings that fiscal or monetary
policies, economic controls or new federal or state legislation may have in the
future.

         The information contained in note 11 of the Notes to Consolidated
Financial Statements on pages 39 and 40 of the Southside Bancshares Corp. 1996
Annual Report is incorporated herein by reference.

         (c)     Competition

         The Registrant and its subsidiaries encounter substantial competition
in all aspects of their banking activities.  New banks may be established in
the market areas of the subsidiary banks, and the location of existing banks
may be moved on occasion.  In addition, competing banks and competing bank
holding companies are continuing to establish separate banking facilities or
branches which have been permitted under Missouri law since 1972.  Any such new
or relocated banks and facilities may have a tendency to increase the
competition faced by the subsidiary banks.  Missouri law permits unlimited,
state-wide branching for both national and state-chartered banks, subject to
certain criteria.

         As lenders, the subsidiary banks compete not only with other banks but
also with savings and loans associations, credit unions, finance companies,
insurance companies and other non-banking financial institutions that offer
credit.  The subsidiary banks also compete for savings and time deposits with
other banks, savings and loan associations, credit unions, money market and
mutual funds, and issuers of commercial paper, securities and various forms of
fixed and variable income investments.  The principal competitive factors in
the markets for deposits and loans are interest rates paid and interest rates
charged, along with related services; accessibility to customers is also a
substantial factor.

         (d)     Monetary Policy and Economic Conditions

         The principal sources of funds to banks and bank holding companies are
deposits, stockholders' equity and borrowed funds.  Stockholders' equity is
represented by common stock, surplus and retained earnings, as well as current
net income.  Borrowed funds include short-, intermediate- and long-term debt,
as well as Federal funds purchased and securities sold under agreements to
repurchase.  The availability of these various sources of funds and other
potential sources, such as preferred stock, convertible securities and
commercial paper, and the extent to which they are utilized, depends on many
factors, the most important of which are the monetary policies of the Federal
Reserve Board and the relative costs of different types of funds.

         An important function of the Federal Reserve Board is to regulate the
national supply of bank credit.  Among the instruments of monetary policy used
by the Federal Reserve Board to implement these objectives are open market
operations in United States Government Securities, changes in the discount rate
on bank borrowings and changes in reserve requirements against bank deposits.
The foregoing means are used in varying combinations to influence overall
growth of bank loans.  Investments and deposits may also affect interest rates
charged on loans and paid for deposits.  The availability and cost of various
sources of funds are also affected by fiscal policies of the United States
Government.





                                       4
<PAGE>   6

         The monetary policies of the Federal Reserve Board and the fiscal
policies of the United States Government have had a significant effect on
operating results of commercial banks in the past and are expected to continue
to do so in the future.  No prediction can be made as to future changes in
interest rates, credit availability, deposit levels, loan demand or the overall
performance of banks generally and the subsidiaries of Southside in particular.

         (e)     Statistical Information

         The following selected statistical information relative to Southside
and its subsidiaries should be read in conjunction with Management's Discussion
and Analysis of Financial Condition and Results of Operations, the Consolidated
Financial Statements and Notes to Consolidated Financial Statements included in
the Southside Bancshares Corp. 1996 Annual Report, incorporated herein by
reference.

                        SELECTED STATISTICAL INFORMATION
I.       Loan Portfolio

         A.      Types of Loans

         The following table shows the classification of loans by major
category at December 31 for the years shown.


<TABLE>
<CAPTION>
                                                                    (in thousands)

                                           -----------------------------------------------------------------------------------
                                               1996          1995            1994         1993          1992
                                           -----------------------------------------------------------------------------------
<S>                                           <C>             <C>          <C>           <C>          <C>
Commercial, financial
 and agricultural                              $62,016        $ 62,214     $ 69,219      $ 73,566     $ 88,026
Real estate-commercial                          82,045          88,321       82,807        86,258       90,860
Real estate-construction                        26,067          15,510       11,019         9,540       17,555
Real estate-residential                         96,039         102,418      108,134       110,806      132,941
Consumer                                        17,304          17,626       18,334        18,849       19,797
Industrial revenue bonds                         6,373           7,789        9,311         8,544       10,841
Other loans                                      4,619           9,946        2,573           668          839
                                               -------         -------      -------       -------      -------

  TOTAL LOANS                                 $294,463        $303,824     $301,397      $308,231     $360,859
                                               =======         =======      =======       =======      =======
</TABLE>


      B.      Maturities and Sensitivities of Loans to Changes in Interest Rates

         The following table shows the remaining maturities of selected loan
                                                  categories at December 31,
                                                  1996.  (in thousands)
<TABLE>
<CAPTION>

                                           ----------------------------------------------------------------------------------------
                                              One year          Over one up            Over
                                              or less*          to 5 years           5 years          Total
                                           ----------------------------------------------------------------------------------------
<S>                                               <C>                 <C>               <C>           <C>
Commercial, financial
 and agricultural                                 $44,615             $16,178           $1,223        $62,016
Real estate-construction                           22,300               3,767              -           26,067
Other loans                                         4,619                -                 -            4,619
                                                   ------             -------           ------         ------
     TOTAL                                        $71,534             $19,945           $1,223        $92,702
                                                   ------              ------            -----         ------
</TABLE>
*        Demand loans, loans having no stated schedule of repayments and no
         stated maturity, and overdrafts are reported as due "One year or
         less."





                                       5
<PAGE>   7

The following table shows the amount of loans above having maturities over one
year which have predetermined interest rates, and the amount which have
floating or adjustable interest rates at December 31, 1996 (in thousands).

<TABLE>
<S>                                                                 <C>
Loans with predetermined interest rates                              $19,130
Loans with floating or adjustable interest rates                       2,038
                                                                      ------
                                                                     $21,168
                                                                     =======
</TABLE>

II.      Summary of Loan Loss Experience

         The information under the caption Allowance for Loan Losses and Risk
Elements on pages 8 through 10 of the Southside Bancshares Corp.  1996 Annual
Report is incorporated herein by reference.

         The following table analyzes the loan loss experience of the
Registrant for the periods indicated:

<TABLE>
<CAPTION>
                                                                     (dollars in thousands)
                                                                    Years Ended December 31,

                                           ----------------------------------------------------------------------------------------
                                               1996          1995            1994         1993          1992
                                           ----------------------------------------------------------------------------------------
<S>                                       <C>              <C>           <C>           <C>          <C>
Average loans outstanding, net of
  unearned discount                         $295,683         $297,480      $294,749      $330,869     $394,967
                                             =======          =======       =======       =======      =======

Allowance at beginning of year              $  5,635         $  7,144      $  8,334      $  9,994     $  6,646
                                            --------         --------      --------      --------     --------

Loans charged off:
  Commercial, financial and
     agricultural                                878            1,606           821         3,087        1,976
  Real estate - construction                      -              -             -              -            -
  Real estate - residential                       93              294         1,302         1,884        1,290
  Consumer                                       248              274           195           528          975
                                              ------          -------       -------       -------      -------

  Total loans charged off                      1,219            2,174         2,318         5,499        4,241
                                              ------          -------       -------       -------      -------

Recoveries:
  Commercial, financial and
     agricultural                                869              661           276           615          278
  Real estate - construction                      -                -             -             -            -
  Real estate - mortgage                         171              186           568           531            6
  Consumer                                        86               75            91            85           63
                                              ------          -------       -------       -------      -------

  Total recoveries                             1,126              922           935         1,231          347
                                              ------          -------       -------       -------      -------

Net loans charged off                             93            1,252         1,383         4,268        3,894
                                              ------          -------       -------       -------      -------

Provisions charged to
  operating expense                               60               70           193         2,608        7,242
                                              ------          -------       -------       -------      -------

Adjustment due to sale of
  Bay-Hermann-Berger Bank                        -               (327)           -             -            -
                                              ------          --------      -------       -------      -------

Allowance at end of year                     $ 5,602         $  5,635      $  7,144      $  8,334     $  9,994
                                              ======          =======       =======       =======      =======

Ratio of net charge-offs during
  year to average loans outstanding             0.03%            0.42%         0.47%         1.29%        0.99%
                                              ======          =======       =======      ========      =======
</TABLE>





                                       6
<PAGE>   8

         The following table sets forth at the end of each reported period, a
breakdown of the allowance for possible loan losses by major categories of
loans and the percentage of loans in each category to total loans at the dates
indicated:

<TABLE>
<CAPTION>
                                                            Years Ended December 31,
                                                              (dollars in thousands)

                   ----------------------------------------------------------------------------------------------------------------
                         1996                   1995                 1994                 1993                  1992
                   ----------------------------------------------------------------------------------------------------------------
                            Percent of              Percent of            Percent of             Percent of            Percent of
                            Loans in Each           Loans in Each         Loans in Each          Loans in Each         Loans in Each
                            Category To             Category To           Category To            Category To           Category To
                 Allowance  Total Loans  Allowance  Total Loans Allowance Total Loans  Allowance Total Loans Allowance Total Loans
                 ---------  -----------  ---------  ----------- --------- -----------  --------- ----------- ---------  -----------
<S>                <C>      <C>          <C>         <C>        <C>        <C>         <C>        <C>         <C>         <C>
Commercial,
  financial and
  agricultural      $3,902    23.2%      $3,935       23.0%     $5,094     26.0%        $5,984     26.6%      $6,644     27.4%

Real estate -
  construction        300     8.9%          300        5.1%        300      3.7%           300      3.1%         300      4.9%

Real estate -
  mortgage          1,000    60.5%        1,000       62.8%      1,500     63.4%         1,500     63.9%       2,000     62.0%

Consumer loans to
  individuals         200     5.8%          200        5.8%        200      6.1%           500      6.2%       1,000      5.5%

Other loans
  (Unallocated)       200     1.6%          200        3.3%         50      0.8%            50      0.2%          50      0.2%
                    -----    -----       ------     --------    -------  --------      --------  --------    --------  --------
                   $5,602   100.0%      $ 5,635      100.0%    $ 7,144    100.0%       $ 8,334    100.0%     $ 9,994    100.0%
                    =====   ======       ======     ========    =======  ========      ========  ========    ========  ========
</TABLE>





                                       7
<PAGE>   9

III.     Investment Portfolio

         The information contained in note 2 of the Notes to Consolidated
Financial Statements on pages 34 and 35 of the Southside Bancshares Corp. 1996
Annual Report is incorporated herein by reference.  The following table
summarizes the carrying values and weighted average yields of investments in
debt securities by contractual maturity.  Actual maturities will differ from
contractual maturities, because borrowers have the right to prepay obligations
with or without prepayment penalties.  A maturity distribution for
mortgage-backed securities has not been prepared due to their accelerated
prepayment characteristics.

<TABLE>
<CAPTION>
                                                                             (dollars in thousands)
                                                                                DECEMBER 31, 1996
                                                          --------------------------------------------------------

                                                              AVAILABLE FOR SALE                  HELD TO MATURITY
                                                              ------------------                  ----------------

                                                          CARRYING          AVERAGE          CARRYING          AVERAGE
                                                           VALUE            YIELD*            VALUE             YIELD*
                                                           -----            -----             -----             -----
 <S>                                                       <C>                  <C>          <C>                   <C>
 U.S. TREASURY SECURITIES AND OBLIGATIONS OF U.S.
    GOVERNMENT AGENCIES AND CORPORATIONS:

       Within 1 year                                        $4,713              5.83%         $23,808              5.32%
       After 1 but within 5 years                           13,724              5.87           59,471              5.98

       After 5 but within 10 years                             408              6.00            9,190              5.83

       After 10 years                                          -                 -                -                 -
                                                           -------                           --------
                        Total                               18,845              5.87           92,469              5.80
                                                           =======                           ========

 OBLIGATIONS OF STATES AND POLITICAL SUBDIVISIONS:
       Within 1 year                                           146              4.45              620              6.23

       After 1 but within 5 years                              305              7.21            8,536              6.06

       After 5 but within 10 years                               -                 -           11,232              5.32
       After 10 years                                            -                 -            1,321              5.90
                                                           -------                           --------

                        Total                                  451              6.31           21,709              5.67
                                                           =======           =======         ========           =======
 OTHER DEBT SECURITIES:

       Within 1 year                                             -                 -                -                 -

       After 1 but within 5 years                            1,179              6.25              300              6.00
       After 5 but within 10 years                               -                 -                -                 -

       After 10 years                                          100              6.29              -                 -
                                                           -------                           --------           -------
                        Total                                1,279              6.25              300              6.00
                                                           =======           =======         ========           =======

 TOTAL INVESTMENT SECURITIES:

       Within 1 year                                         4,859              5.78           24,428              5.33
       After 1 but within 5 years                           15,208              5.90           68,307              5.99

       After 5 but within 10 years                             408              6.00           20,422              5.55
       After 10 years                                          100              6.29            1,321              5.90
                                                           -------                           --------

                        Total                               20,575              5.90          114,478              5.77
                                                           =======           =======         ========           =======

 MORTGAGE-BACKED SECURITIES                                 46,075              6.29            6,166              7.15
                                                           =======           =======         ========           =======
                        Total                              $66,650              6.17         $120,644              5.85
                                                           =======           =======         ========           =======
</TABLE>

*  The weighted average yield for each maturity range was calculated using the
   yield on each security within that range, weighted by the amortized cost of
   each security at December 31, 1996.  The yields for obligations of states
   and political subdivisions exempt from federal income taxes have been
   adjusted to a fully tax-equivalent basis at a maximum tax rate of 34% for
   1996, adjusted for the disallowance of interest cost to carry nontaxable
   securities.





                                       8
<PAGE>   10

ITEM 2.  PROPERTIES

         The Registrant owned the following physical properties as of December
31, 1996:

         South Side National Bank in St. Louis, a subsidiary of the Registrant,
owns a nine-story banking and office building at 3606 Gravois Avenue in St.
Louis, Missouri 63116, and the adjacent drive-up facilities and three parking
lots.  The Registrant and this subsidiary occupy all nine stories in the
building.  This subsidiary of the Registrant owns the land and bank building
located at its branch facility at 10330 Gravois Road, St. Louis, Missouri
63126.  This is a two story building and the lower level and a portion of the
main level are leased to tenants for an annual rental of approximately $34,000.
This subsidiary also owns the land and bank building at 9914 Kennerly Road in
St. Louis County upon which its South County branch is located. This is a
two-story building and the second floor is leased to tenants for an annual
rental of approximately $83,000.  This subsidiary also owns the land and bank
buildings at 10385 West Florissant, Ferguson, Missouri 63136, 8440 Morganford
Road, St. Louis County, Missouri 63123 and 3420 Iowa Street, St. Louis,
Missouri 63118.  This subsidiary leases a branch facility at 4666 Lansdowne,
St. Louis, Missouri 63116.

         State Bank of DeSoto owns the land and a two-story building at its
main banking office at 224 S. Main Street, DeSoto, Missouri 63020.  The State
Bank of DeSoto also owns the land and a one-story building housing its facility
located at 2000 Rock Road, DeSoto, Missouri 63020.

         Bank of Ste. Genevieve owns the land, a one-story building and an
adjacent parking lot at its main banking office at Second and Market Streets,
Ste. Genevieve, Missouri 63670 and the land and one-story building at its
facility at 710 Parkwood Drive, Ste. Genevieve, Missouri 63670.

         The Bank of St. Charles County owns the land and a two-story building
at its banking facility at 6004 Highway 94 South, St. Charles, Missouri 63304.
This subsidiary bank occupies one story in the building and leases
approximately 5,000 square feet for an annual rental of approximately $19,000.
This subsidiary bank owns the land and a one-story building at its facility
located at 750 First Capitol Drive, St. Charles, Missouri 63301.

         In the opinion of the Registrant's management, the physical properties
of the subsidiary banks are suitable and adequate and are being productively
utilized.


ITEM 3.  LEGAL PROCEEDINGS

         The information contained in note 13 of the Notes to Consolidated
Financial Statements on page 41 of the Southside Bancshares Corp.  1996 Annual
Report is incorporated herein by reference.


ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

         None.





                                       9
<PAGE>   11



EXECUTIVE OFFICERS OF THE REGISTRANT

         The following is a list of the names and ages of the executive
officers of the Registrant and their business history for the past five years:

<TABLE>
<CAPTION>
 NAME, AGE AND POSITION WITH THE
 COMPANY                                PRINCIPAL OCCUPATIONS OR EMPLOYMENT SINCE JANUARY 1, 1992
 ------------------------------------   ---------------------------------------------------------
 <S>                                    <C>
 Thomas M. Teschner (40)                President and Chief Executive Officer, Southside Bancshares Corp.
 President and Chief Executive          (Since June 1992); President and Chief Executive Officer, South Side
 Officer                                National Bank in St. Louis (Since October 1992); Senior Vice President
                                        and Senior Loan Officer, South Side National Bank in St. Louis and
                                        Southside Bancshares Corp. (September 1986 - June 1992).

 Joseph W. Pope (31)                    Chief Financial Officer and Senior Vice President, Southside
 Senior Vice President and              Bancshares Corp. (Since April 1995); Vice President, South Side
 Chief Financial Officer                National Bank in St. Louis (Since November 1992); Certified Public
                                        Accountant, KPMG Peat Marwick LLP (August 1987 - November 1992).
</TABLE>


                                    PART II

ITEM 5.  MARKET FOR THE REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER
MATTERS

         The only class of the Registrant's common equity is common stock,
$1.00 par value (the "Common Stock").  The number of shares of Common Stock of
the Registrant outstanding at March 17, 1997 was 2,835,670 shares, and the
market price for the Common Stock on March 17, 1997 was $23.50 bid; $28.50
asked.

         The information on page 25 of the Southside Bancshares Corp. 1996
Annual Report to Shareholders is incorporated herein by reference.


ITEM 6.  SELECTED FINANCIAL DATA

         The information on page 5 of the Southside Bancshares Corp. 1996
Annual Report to Shareholders is incorporated herein by reference.

ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
RESULTS OF OPERATION

         The information on pages 6 through 25 of the Southside Bancshares
Corp. 1996 Annual Report to Shareholders is incorporated herein by reference.

ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

         The information on pages 26 through 43 of the Southside Bancshares
Corp. 1996 Annual Report to Shareholders is incorporated herein by reference.





                                       10
<PAGE>   12


ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
FINANCIAL DISCLOSURE

         None.


                                    PART III

ITEM 10.         DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

         The information on pages 4 through 6 of the Southside Bancshares Corp.
Proxy Statement for the Annual Meeting of Shareholders scheduled for April 24,
1997 is incorporated herein by reference.  The information on page 16 of the
Southside Bancshares Corp. Proxy Statement for the Annual Meeting of
Shareholders scheduled for April 24, 1997, with respect to compliance by the
Registrant's officers and directors with Section 16(a) of the Securities
Exchange Act of 1934, is incorporated herein by reference.  The required
information regarding Southside's executive officers is contained in PART I in
the item captioned "Executive Officers of the Registrant."


ITEM 11.         EXECUTIVE COMPENSATION

         The information on pages 6 through 11 of the Southside Bancshares
Corp. Proxy Statement for the Annual Meeting of Shareholders scheduled for
April 24, 1997 is incorporated herein by reference.


ITEM 12.         SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

         The information on pages 3 and 4 of the Southside Bancshares Corp.
Proxy Statement for the Annual Meeting of Shareholders scheduled for April 24,
1997, is incorporated herein by reference.


ITEM 13.         CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

         The information on page 15 of the Southside Bancshares Corp. Proxy
Statement for the Annual Meeting of Shareholders scheduled for April 24, 1997,
is incorporated herein by reference.


                                    PART IV


ITEM 14.         EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM
8-K

(a)      The following financial statements of Southside and its consolidated
         subsidiaries, and the accountants' report thereon are incorporated
         herein by reference in Item 8.

         1.      Financial Statements:

                 Independent Auditors' Report

                 Consolidated Balance Sheets -
                          December 31, 1996 and 1995





                                       11
<PAGE>   13

                 Consolidated Statements of Income -
                          Years Ended December 31, 1996, 1995 and 1994

                 Consolidated Statements of Shareholders' Equity -
                          Years Ended December 31, 1996, 1995 and 1994

                 Consolidated Statements of Cash Flows -
                          Years Ended December 31, 1996, 1995 and 1994

                 Notes to Consolidated Financial Statements

          2.     Financial Statement Schedules:

                 All other schedules are omitted because they are not
         applicable, not required, or the information is included elsewhere in
         the Consolidated Financial Statements or notes thereto.

<TABLE>
          <S>    <C>
          3.     Exhibits:*

                 3(a)     Restated Articles of Incorporation of the Registrant filed as Exhibit 4(a) to the
                          Registrant's Registration Statement on Form S-8 on May 2, 1994, incorporated herein by
                          reference.

                 3(b)     Restated Bylaws of the Registrant with amendments through December 28, 1995 filed as
                          Exhibit 4(b) to the Registrant's Registration Statement on Form S-8 on January 31, 1996,
                          incorporated herein by reference.

                 4(a)     Rights Agreement dated as of May 27, 1993 between the Registrant and Boatmen's Trust Company
                          filed as Exhibits 1 and 2 to the Registrant's Registration Statement on Form 8-A on May 27,
                          1993, incorporated herein by reference.

                 10(a)    Employment Agreement Dated April 27, 1995 between Southside Bancshares Corp., South Side
                          National Bank in St. Louis and Thomas M. Teschner filed as Exhibit 10(b) to the Registrant's
                          Report on Form 10-K for the fiscal year ended December 31, 1995, incorporated herein by
                          reference.

                 10(b)    Southside Bancshares Corp. 1993 Non-Qualified Stock Option Plan, filed as Exhibit 10(e) to
                          the Registrant's Report on Form 10-K for the fiscal year ended December 31, 1994,
                          incorporated herein by reference.

                 10(c)    Deferred Compensation Agreement dated April 25, 1996 between
                          Thomas M. Teschner and Southside Bancshares Corp.

                 10(d)    Southside Bancshares Corp. Deferred Compensation Plan for
                          Directors

                 11       Computation of Net Income Per Common Share

                 13       Portions of the Annual Report to Shareholders of the Registrant for the fiscal year ended
                          December 31, 1996.
</TABLE>





                                       12
<PAGE>   14


<TABLE>
                 <S>      <C>
                 21       List of Subsidiaries.

                 23       Independent Auditors' Consent of KPMG Peat Marwick LLP.

                 27       Financial Data Schedule.
</TABLE>

*        The exhibits included under Exhibit 10 constitute all management
         contracts, compensatory plans and arrangements required to be filed as
         an exhibit to this form pursuant to Item 14(c) of this report.


(b)      Reports filed on Form 8-K:

                 The following reports on Form 8-K were filed for the three
months ended December 31, 1996:

                 None.





                                       13
<PAGE>   15

                                   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.


                                        SOUTHSIDE BANCSHARES CORP.




<TABLE>
          <S>                                      <C>
                                                   By       /s/ Thomas M. Teschner
                                                      ------------------------------------------------------------------------
                                                            Thomas M. Teschner
                                                            President and Chief Executive Officer
                                                            (Principal Executive Officer)
March 28, 1997


                                                   By       /s/ Joseph W. Pope
                                                      ---------------------------------------------------------------------------
                                                            Joseph W. Pope
                                                            Senior Vice President and Chief Financial Officer (Principal
                                                            Financial Officer, Controller and Principal Accounting Officer)
March 28, 1997
</TABLE>

         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 and on the dates indicated.




<TABLE>
<S>      <C>                                                <C>     <C>
         /s/ Howard F. Etling                                       /s/ Joseph W. Beetz
---------------------------------------------------         ----------------------------------------------------------------------
         Howard F. Etling                                           Joseph W. Beetz
         Chairman of the Board                                      Director

Date:  March 28, 1997                                     Date:  March 28, 1997



         /s/ Ralph Crancer, Jr.                                     /s/ Douglas P. Helein
---------------------------------------------------         -----------------------------------------------------------------------
         Ralph Crancer, Jr.                                         Douglas P. Helein
         Director                                                   Director

Date:  March 28, 1997                                     Date:  March 28, 1997


         /s/ Thomas M. Teschner                                     /s/ Earle J. Kennedy, Jr.
---------------------------------------------------         ----------------------------------------------------------------------
         Thomas M. Teschner                                         Earle J. Kennedy, Jr.
         President, Chief Executive Officer and                     Director
         Director

Date:  March 28, 1997                                     Date:  March 28, 1997
</TABLE>

<PAGE>   16

<TABLE>
<S>                                                                 <C>
         /s/ Norville K. McClain                                    /s/ Richard G. Schroeder, Sr.
---------------------------------------------------         -----------------------------------------------------------
         Norville K. McClain                                        Richard G. Schroeder, Sr.
         Director                                                   Director

Date:  March 28, 1997                                     Date:  March 28, 1997



         /s/ Daniel J. Queen
---------------------------------------------------
         Daniel J. Queen
         Director

Date:  March 28, 1997
</TABLE>

<PAGE>   17

                                 EXHIBIT INDEX


<TABLE>
<CAPTION>
    REGULATION S-K                                                                                          REPORT
        EXHIBIT                                                                                              PAGE
          NO.                                             DESCRIPTION                                         NO.
     ------------                                         -----------                                      --------

         <S>            <C>                                                                                     <C>
         3(i)           Restated Articles of Incorporation of the Registrant filed as Exhibit 4(a) to           *
                        the Registrant's Registration Statement on Form S-8 on May 2, 1994
                        (No. 33-78454), incorporated herein by reference.

         3(ii)          Restated Bylaws of the Registrant with amendments through December 28, 1995             *
                        filed as Exhibit 4(b) to the Registrant's Registration Statement (No. 333-
                        00579) on Form S-8 on January 31, 1996, incorporated herein by reference.

         4(a)           Rights Agreement dated as of May 27, 1993 between Registrant and Boatmen's              *
                        Trust Company filed as Exhibits 1 and 2 to Registrant's Registration Statement
                        on Form 8-A on June 1, 1993 (No. 0-10849), incorporated herein by reference.

         10(a)          Employment Agreement Dated April 27, 1995 between Registrant, South Side                *
                        National Bank in St. Louis and Thomas M. Teschner filed as Exhibit 10(b) to
                        the Registrant's Report on Form 10-K for the fiscal year ended December 31,
                        1995, incorporated herein by reference.

         10(b)          Southside Bancshares Corp. 1993 Non-Qualified Stock Option Plan, filed as               *
                        Exhibit 10(e) to the Registrant's Report on Form 10-K for the fiscal year
                        ended December 31, 1994, incorporated herein by reference.

         10(c)          Deferred Compensation Agreement dated April 25, 1996 between Thomas M.
                        Teschner and Southside Bancshares Corp., filed herewith.

         10(d)          Southside Bancshares Corp. Deferred Compensation Plan for Directors, filed
                        herewith.

          11            Computation of Net Income Per Common Share, filed herewith.

          13            Portions of the Annual Report to Shareholders of the Registrant for the fiscal
                        year ended December 31, 1996, filed herewith.

          21            List of Subsidiaries, filed herewith.

          23            Independent Auditors' Consent of KPMG Peat Marwick LLP, filed herewith.

          27            Financial Data Schedule, filed herewith.
</TABLE>

         *       Incorporated by reference.