<PAGE>
                                                                     EXHIBIT 4.3

                     SOUTHWEST BANCORPORATION OF TEXAS, INC.
                    NON-EMPLOYEE DIRECTORS DEFERRED FEE PLAN

         1. Purpose. The purpose of the Plan is to provide Non-Employee
Directors an opportunity to defer payment of all or a portion of their
Director's Fees in accordance with the terms and conditions set forth herein.

         2. Definitions. For the purposes of the Plan, the following capitalized
words shall have the meanings set forth below:

         "Bank" means Southwest Bank of Texas National Association, a
wholly-owned subsidiary of the Company.

         "Bank Board" means the Board of Directors of the Bank.

         "Board" means the Board of Directors of the Company.

         "Committee" means the committee of the Board which has been appointed
by the Board to administer the Plan or, if none, the Board.

         "Common Stock" means the common stock, par value $1.00 per share, of
the Company.

         "Company" means Southwest Bancorporation of Texas, Inc.

         "Deferral Election Form" means a document, in a form approved by the
Company, pursuant to which a Non-Employee Director makes a deferral election
under the Plan.

         "Deferral Period" means each calendar year. The first Deferral Period
under the Plan shall commence January 1, 2002. If an individual becomes eligible
to participate in the Plan after the commencement of a Deferral Period, the
Deferral Period for that individual shall be the remainder of such Deferral
Period following his Election Date.

         "Deferred Benefit" means an amount that will be paid on a deferred
basis under the Plan.

         "Deferred Compensation Account" means the bookkeeping account
established for each Non-Employee Director for purposes of measuring his or her
Deferred Benefit and shall include subaccounts for Deferred Benefits that are to
be paid at different times and/or in a different manner.

         "Director's Fee" means the cash portion of the annual retainer fee and
any other fees payable for service on the Board or the Bank Board, including,
without limitation, any meeting fees or fees for serving as a chair of any
committee of the Board or the Bank Board.

         "Election Date" means the day immediately preceding the commencement of
a Deferral Period. If an individual first becomes eligible to participate in the
Plan after the start of a Deferral Period, the Election Date shall be not later
than the thirtieth day following the initial date such individual became a
Non-Employee Director.
<PAGE>

         "Fair Market Value" means the closing sales price of a share of Common
Stock on the applicable date (or, if there was no trading in the shares on such
date, on the next preceding date on which there was trading) on the principal
exchange or system on which the shares are sold, as reported in The Wall Street
Journal or other reporting service approved by the Committee.

         "Non-Employee Director" means a member of the Board or the Bank Board
who is not an employee of the Company or any of its subsidiaries.

         "Phantom Stock Unit" means a bookkeeping unit representing the
equivalent in value of one share of Common Stock.

         "Plan" means the Southwest Bancorporation of Texas, Inc. Non-Employee
Director Deferred Fee Plan.

         3. Administration.

            (a) The Plan shall be administered by the Committee.

            (b) The Committee shall be authorized to interpret the Plan, to
         establish, amend and rescind any rules and regulations relating to the
         Plan, to make factual determinations in connection with the
         administration or interpretation of the Plan, and to make any other
         determinations that it believes are necessary or advisable for the
         administration of the Plan. The Committee may correct any defect or
         supply any omission or reconcile any inconsistency in the Plan or in
         any Deferral Election Form to the extent the Committee deems desirable
         to carry the Plan into effect. Any decision of the Committee in the
         administration of the Plan shall be final and conclusive. The Committee
         may act only by a majority of its members, except that the members
         thereof may authorize any one or more of the Committee members to
         execute and deliver documents on behalf of the Committee.

            (c) Each member of the Committee and each other person acting at the
         direction of or on behalf of the Committee shall not be liable for any
         determination or anything done or omitted to be done by him or by any
         other member of the Committee or any other such individual in
         connection with the Plan, except for his own gross negligence or
         willful misconduct or as expressly provided by statute, and to the
         extent permitted by law and the bylaws of the Company, shall be fully
         indemnified and protected by the Company with respect to such
         determination, act or omission.

         4. Shares Available. The Company is authorized to credit up to 25,000
Phantom Stock Units and to issue up to 25,000 shares of Common Stock,
respectively, under the Plan (the "Plan Limit"). Such shares of Common Stock may
be newly issued shares of Common Stock or reacquired shares of Common Stock held
in the treasury of the Company.

         5. Deferral of Director's Fees.

            (a) Deferral Elections.




                                                                             -2-
<PAGE>

                            (i) General Provisions. Unless the Committee
                   provides otherwise, Non-Employee Directors may elect to defer
                   all, one-half or none of their Director's Fees with respect
                   to a Deferral Period in the manner provided in this Section
                   5. A Non-Employee Director's Deferred Benefit is at all times
                   nonforfeitable.

                            (ii) Deferral Election Forms. In order for a
                   Non-Employee Director to participate in the Plan for a given
                   Deferral Period, a Deferral Election Form, completed and
                   signed by him, must be delivered to the Company on or prior
                   to the applicable Election Date. A new Deferral Election Form
                   must be submitted by a Non-Employee Director for each
                   Deferral Period. A Non-Employee Director electing to
                   participate in the Plan for a given Deferral Period shall
                   indicate on his Deferral Election Form:

                                     (A) the percentage of the Director's Fees
                            for the Deferral Period to be deferred, which
                            election shall be irrevocable for such Deferral
                            Period, and

                                     (B) the timing and manner of payment of the
                            Director's Fees deferred for that Deferral Period.
                            Any subsequent change as to the timing and manner of
                            payment of Deferred Benefits already credited to the
                            Non-Employee Director's Deferred Compensation
                            Account shall not be effective if (i) the
                            Non-Employee Director ceases to be a member of the
                            Board and Bank Board within 12 months following the
                            date of such election change or (ii) the change is
                            made less than 12 months prior to a previously
                            elected payment date, unless the Committee consents
                            to such change.

                            (iii) Effect of No Deferral Election. A Non-Employee
                   Director who does not have a completed Deferral Election Form
                   on file with the Company on or prior to the applicable
                   Election Date for a Deferral Period may not defer his
                   Director's Fees for such Deferral Period.

            (b) Establishment of Deferred Compensation Accounts. A Non-Employee
         Director's deferrals will be credited to a Deferred Compensation
         Account set up for that Non-Employee Director by the Company in
         accordance with the provisions of this Section 5.

            (c) Crediting of Phantom Stock Units to Deferred Compensation
         Accounts.

                            (i) Number of Phantom Stock Units. The portion of
                   the Director's Fees that a Non-Employee Director elects to
                   defer shall be credited to the Deferred Compensation Account
                   in Phantom Stock Units as of the last business day of the
                   fiscal quarter in which such portion of the Director's Fees
                   would otherwise have been payable to the Non-Employee
                   Director in cash. The number of Phantom Stock Units to be
                   credited to the Deferred Compensation Account shall be
                   determined by dividing (1) the amount of the Director's Fees
                   deferred during




                                                                             -3-
<PAGE>

                   such quarter by (2) the Fair Market Value of a share of
                   Common Stock as of the date of crediting, and (3) multiplying
                   such result by 1.25. Any partial Phantom Stock Unit that
                   results from the application of the previous sentence shall
                   be rounded up to the nearest whole Phantom Stock Unit.

                            (ii) Dividend Equivalents. In the event that the
                   Company pays any cash or other dividend or makes any other
                   distribution in respect of the Common Stock, the Deferred
                   Compensation Account of a Non-Employee Director will be
                   credited with additional Phantom Stock Units determined by
                   dividing (A) the amount of cash, or the value (as determined
                   by the Committee) of any securities or other property, paid
                   or distributed in respect of a corresponding number of shares
                   of Common Stock by (B) the Fair Market Value of a share of
                   Common Stock as of the date of such payment or distributions.
                   Any partial Phantom Stock Unit that results from the
                   application of the previous sentence shall be rounded up to a
                   whole Phantom Stock Unit. Such credit shall be made effective
                   as of the date of the dividend or other distribution in
                   respect of the Common Stock.

                            (iii) No Rights as Stockholder. The crediting of
                   Phantom Stock Units to a Non-Employee Director's Deferred
                   Compensation Account shall not confer on the Non-Employee
                   Director any rights as a stockholder of the Company.

                   (d) Written Statements of Account. The Company will furnish
          each Non-Employee Director with a statement setting forth the value of
          such Non-Employee Director's Deferred Compensation Account as of the
          end of each Deferral Period and all credits to and payments from the
          Deferred Compensation Account during the Deferral Period. Such
          statement will be furnished as soon as reasonably practical after the
          end of the Deferral Period.

                   (e) Manner of Payment of Deferred Benefit. Payment of the
          Deferred Benefits shall be in shares of Common Stock. Payment shall be
          made either in a single lump sum or in a series of five or fewer
          annual installments, as elected by the Non-Employee Director. The
          amount of each installment payment to a Non-Employee Director shall be
          determined in accordance with the formula B/(N-P), where "B" is the
          total value of the Deferred Compensation Account as of the installment
          calculation date, "N" is the number of installments elected by the
          Non-Employee Director and "P" is the number of installments previously
          paid to the Non-Employee Director. Any partial unit resulting in the
          calculation above will be settled in cash.

                   (f) Commencement of Payment of Deferred Benefit. Payment of a
          Non-Employee Director's Deferred Compensation Account, including
          subaccounts, shall commence as soon as reasonably practicable after
          the earlier to occur of:

                       (i) his or her termination as a member of the Board and
                   the Bank Board; and

                       (ii) the date specified in the Deferral Election Form
                   executed by the Non-Employee Director.




                                                                             -4-
<PAGE>

                   (g) Death. In the event of a Non-Employee Director's death,
          the Non-Employee Director's entire Deferred Benefit will be
          distributed in a lump sum to the Non-Employee Director's beneficiary
          as soon as reasonably practicable after the date of death.

                   (h) Restrictions on Transfer. The Company shall pay all
          Deferred Benefits payable under the Plan only to the Non-Employee
          Director or beneficiary designated under the Plan to receive such
          amounts. Neither a Non-Employee Director nor his beneficiary shall
          have any right to anticipate, alienate, sell, transfer, assign,
          pledge, encumber or change any benefits to which he may become
          entitled under the Plan, and any attempt to do so shall be void. A
          Deferred Benefit shall not be subject to attachment, execution by
          levy, garnishment, or other legal or equitable process for a
          Non-Employee Director's or beneficiary's debts or other obligations.

          6. Designation of Beneficiary.

                   (a) Beneficiary Designations. Each Non-Employee Director may
          designate a beneficiary to receive any Deferred Benefit due under the
          Plan on the Non-Employee Director's death by executing a beneficiary
          designation form provided by the Company.

                   (b) Change of Beneficiary Designation. A Non-Employee
          Director may change an earlier beneficiary designation by executing a
          later beneficiary designation form and delivering it to the Company.
          The execution of a beneficiary designation form and its receipt by the
          Company revokes and rescinds any prior beneficiary designation form.

          7. Recapitalization or Reorganization.

                   (a) Authority of the Company and Stockholders. The existence
          of the Plan shall not affect or restrict in any way the right or power
          of the Company or the stockholders of the Company to make or authorize
          any adjustment, recapitalization, reorganization or other change in
          the Company's capital structure or its business, any merger or
          consolidation of the Company, any issue of stock or of options,
          warrants or rights to purchase stock or of bonds, debentures,
          preferred or prior preference stocks having rights superior to or
          affecting the Common Stock or the rights thereof or which are
          convertible into or exchangeable for Common Stock, or the dissolution
          or liquidation of the Company, or any sale or transfer of all or any
          part of its assets or business, or any other corporate act or
          proceeding, whether of a similar character or otherwise.

                   (b) Change in Capitalization. Notwithstanding any other
          provision of the Plan, in the event of any change in the outstanding
          Common Stock by reason of a stock dividend, recapitalization,
          reclassification, reorganization, merger, consolidation, stock split,
          combination, exchange of shares or other transaction: (i) such
          proportionate adjustments as may be necessary (as determined by the
          Committee in its sole discretion) to reflect such change shall be made
          to prevent dilution or enlargement of the rights of Non-Employee
          Directors under the Plan with respect to the aggregate number of
          shares of Common Stock authorized to be awarded under the Plan and the
          number of Phantom



                                                                             -5-
<PAGE>

          Stock Units credited to a Non-Employee Director's Deferred
          Compensation Account, and (ii) the Committee may make such other
          adjustments, consistent with the foregoing, as it deems appropriate in
          its sole discretion.

                   (c) Dissolution or Liquidation. In the event of the proposed
          dissolution or liquidation of the Company, all Deferred Benefits
          credited to the Non-Employee Director's Deferred Compensation Account
          as of the date of the consummation of a proposed dissolution or
          liquidation shall be paid in cash to the Non-Employee Director or, in
          the event of death of the Non-Employee Director prior to payment, to
          the beneficiary thereof on the date of the consummation of such
          proposed action. The cash amount paid for each Phantom Stock Unit
          shall be the Fair Market Value of a share of Common Stock as of the
          date of the consummation of such proposed action.

          8. Plan Limit, Termination and Amendment of the Plan.

                   (a) If the Plan Limit has been reached, no additional
          Director Fees may be deferred after that date and any dividend
          equivalents credited thereafter shall be credited as a bookkeeping
          "cash" amount, rather than as Phantom Stock Units, and shall be
          credited with interest, until paid in cash, at the Company's prime
          rate of interest each valuation date.

                   (b) General Power of Board. Notwithstanding anything herein
          to the contrary, the Board may at any time and from time to time
          terminate, modify, suspend or amend the Plan in whole or in part and,
          upon termination of the Plan, immediately settle all Phantom Stock
          Units in shares of Common Stock notwithstanding any deferral elections
          to the contrary; provided, however, that no such termination,
          modification, suspension or amendment shall be effective without
          stockholder approval if such approval is required to comply with any
          applicable law or stock exchange rule; and, provided further, that the
          Board may not, without stockholder approval, increase the maximum
          number of shares issuable under the Plan, except as provided in
          Section 7(b) above.

          9. Miscellaneous.

                   (a) No Right to Reelection. Nothing in the Plan shall be
          deemed to create any obligation on the part of the Board or Bank Board
          to nominate any of its members for reelection by the Company's
          stockholders, nor confer upon any Non-Employee Director the right to
          remain a member of the Board or Bank Board for any period of time, or
          at any particular rate of compensation.

                   (b) Unfunded Plan.

                            (i) Generally. This Plan is unfunded. Amounts
                   payable under the Plan will be satisfied solely out of the
                   general assets of the Company subject to the claims of the
                   Company's creditors.

                            (ii) Deferred Benefits. A Deferred Benefit
                   represents at all times an unfunded and unsecured contractual
                   obligation of the Company and each Non-Employee Director or
                   beneficiary will be a general unsecured creditor of the




                                                                             -6-
<PAGE>

                   Company. No Non-Employee Director, beneficiary or an other
                   person shall have any interest in any fund or in any specific
                   asset of the Company by reason of any amount credited to him
                   hereunder, nor shall any Non-Employee Director, beneficiary
                   or any other person have any right to receive any
                   distribution under the Plan except as, and to the extent,
                   expressly provided in the Plan. The Company will not
                   segregate any funds or assets for Deferred Benefits or issue
                   any notes or security for the payment of any Deferred
                   Benefits. Any reserve or other asset that the Company may
                   establish or acquire to assure itself of the funds to provide
                   benefits under the Plan shall not serve in any way as
                   security performance of the Company under the Plan.

                   (c) Other Compensation Arrangements. Benefits received by a
          Non-Employee Director pursuant to the provisions of the Plan shall not
          be included in, nor have any effect on, the determination of benefits
          under any other arrangement provided by the Company.

                   (d) Securities Law Restrictions. All certificates for shares
          of Common Stock delivered under the Plan shall be subject to such
          stock-transfer orders and other restrictions as the Executive may deem
          advisable under the rules, regulations, and other requirements of the
          Securities and Exchange Commission or any exchange upon which the
          Common Stock is then listed, and any applicable federal or state
          securities law, and the Committee may cause a legend or legends to be
          put on any such certificates to make appropriate reference to such
          restrictions. No shares of Common Stock shall be issued hereunder
          unless the Company shall have determined that such issuance is in
          compliance with, or pursuant to an exemption from, all applicable
          federal and state securities laws.

                   (e) Expenses. The costs and expenses of administering the
          Plan shall be borne by the Company.

                   (f) Certain references to Company to include Bank. Where
          applicable, e.g., Sections 5 and 9(b), references to the "Company"
          shall include the Bank.

                   (g) Applicable Law. Except as to matters of federal law, the
          Plan and all actions taken thereunder shall be governed by and
          construed in accordance with the laws of the State of Texas without
          giving effect to conflicts of law principles.

                   (h) Effective Date. The Plan shall be effective as of January
          1, 2002.





                                                                             -7-