EXHIBIT 99.1


               ADMINISTAFF CHAIRMAN TO MODIFY 10B5-1 TRADING PLAN

HOUSTON - Dec. 10, 2003 - Administaff, Inc. (NYSE: ASF), the nation's leading
Professional Employer Organization, today announced that Paul J. Sarvadi, its
chairman and chief executive officer, has modified his previously announced
structured, prearranged trading plan to increase the prices at which shares will
be sold thereunder and the number of shares to be sold. Mr. Sarvadi established
the trading plan in March 2003 to diversify his holdings of Administaff stock in
an orderly manner. The original plan provided for the sale of a maximum of
540,000 shares of Administaff common stock, of which 450,000 were sold.

Under the modified trading plan, two of Mr. Sarvadi's family limited
partnerships may sell a maximum of 414,000 shares, approximately 15% of current
holdings, subject to the achievement of predetermined stock prices ranging from
$20 to $42 per share. The plan has been modified during the company's open
window for insider transactions, and is intended to comply with Rule 10b5-1 of
the Securities Exchange Act of 1934. Rule 10b5-1 permits the implementation of a
written plan for selling stock at times when insiders are not in possession of
material nonpublic information and allows them to sell stock on a regular basis
and in a non-discretionary manner, regardless of any subsequent material
nonpublic information they receive.

Administaff is a leading personnel management company that serves as a
full-service human resources department for small and medium-sized businesses
throughout the United States. The company operates 38 sales offices in 21 major
markets. For additional information, visit Administaff's web site at
www.administaff.com.

(Note: The statements contained in this press release that are not historical
facts are forward-looking statements that involve a number of risks and
uncertainties. Therefore, the actual results of future events described in such
forward-looking statements could differ materially from those stated in such
forward-looking statements. Among the factors that could cause actual results to
differ materially are: (i) changes in general economic conditions; (ii)
regulatory and tax developments, including, but not limited to, Administaff's
ability to comply with Revenue Procedure 2002-21 and possible adverse
application of various federal, state and local regulations; (iii) changes in
Administaff's direct costs and operating expenses, including, but not limited
to, increases in health insurance premiums, increases in underlying health
insurance claims trends, workers' compensation rates and state unemployment tax
rates, liabilities for employee and client actions or payroll-related claims,
changes in the costs of expanding into new markets, and failure to manage growth
of Administaff's operations; (iv) the estimated costs and effectiveness of
capital projects and investments in technology and infrastructure, including
Administaff's ability to maintain adequate financing for such projects; (v)
Administaff's ability to effectively implement its 401(k) recordkeeping
services; (vi) the effectiveness of Administaff's sales and marketing efforts,
including the company's marketing arrangements with other companies; (vii) the
failure to sell Administaff Financial Management Services, Inc.; (viii) changes
in the competitive environment in the Professional Employer Organization
industry; (ix) Administaff's liability for worksite employee payroll and
benefits costs; and (x) an adverse final judgment or settlement of claims
against Administaff. These factors are described in further detail in
Administaff's filings with the Securities and Exchange Commission.)