Exhibit 99.1

     SIMPSON MANUFACTURING CO., INC. ANNOUNCES DECLARATION OF CASH DIVIDEND

    DUBLIN, Calif., May 6 /PRNewswire-FirstCall/ -- Simpson Manufacturing Co.,
Inc. announced today that its Board of Directors declared a cash dividend of
$0.05 per share at its meeting on May 3, 2005. The record date for the
dividend is July 7, 2005, and it will be paid on July 27, 2005.

    Simpson Manufacturing Co., Inc., headquartered in Dublin, California,
through its subsidiary, Simpson Strong-Tie Company Inc., designs, engineers
and is a leading manufacturer of wood-to-wood, wood-to-concrete and
wood-to-masonry connectors, fastening systems and pre-fabricated shearwalls.
Simpson Strong-Tie also offers a full line of adhesives, mechanical anchors
and powder actuated tools for concrete, masonry and steel. The Company's other
subsidiary, Simpson Dura-Vent Company, Inc., designs, engineers and
manufactures venting systems for gas and wood burning appliances. The
Company's common stock trades on the New York Stock Exchange under the symbol
"SSD."

    For further information, contact Barclay Simpson at 925-560-9032.

SOURCE  Simpson Manufacturing Co., Inc.
    -0-                             05/06/2005
    /CONTACT:  Barclay Simpson of Simpson Manufacturing Co., Inc.,
+1-925-560-9032/
    /Web site:  http://www.strongtie.com /