Chalmers Hamer, 65, a Washington area businessman, died Tuesday at the Veterans Administration Hospital here after suffering a heart attack and a stroke.

For more than 25 year, he was active in taxicab management and other businesses. He was chairman of the board of Coastline Cab Co's Interstate Two-Way Radio, Inc., vice president and general manager of its purchasing corporation and president of its finance company.

Mr. Hamer also was a member of the board and treasurer of the Taxicab Industry Group and had served on the D.C. Hackers Licens Appeal Board.

He was president of Hamer Realty Co., and a member of the boards of the Amalgamated Casualty Insurance Co. and Orlando W. Dardaen Incorporated Mortgage Bankers, of which he also was treasurer.

Born in Clio, S.C., Mr. Hamer came to Washington in 1929. He served with the Army as a technical sergeant in World War II.

He was active in the Vermont Avenue Baptist Church, where he held a number of offices. He was chairman of the board of trustees at the time of his death.

A 33d degree Mason. Mr. Hamer had served on the United Supreme Council. He was past master of Ionic Lodge No. 17 and past treasurer and member of the board of Acacia Masonic Hall Association. He also was a Shriner and a Noble at Mecca Temple 10.

Mr. Hamer was a life-member of the NNACP and an active member of the Capitol Hill Kiwanis Club. He had recieved honors from both organizations.

He is survived by his wife, Roberta, of the home in Washington: a son, Chalmers Jr., and a daughter, Peggie Hamer Darden, both of Washington; his mother, Martha Hamer, of Clio, five sister, two brothers and two grandchildren.

The family suggests that expressions of sympathy may be in the form of contributions to the Howard Universtiy Scholarship Fund.