William E. Gartner Sr., 65, a retired Montgomery County assessor and a well known golfer here, died Dec. 7 at Suburban Hospital in Bethesda. He suffered from a heart ailment.

He had served as a certified assessor evaluator-hearing agent in the county's division of assessments from 1952 until retiring in 1973.

Born in Gaithersburg, Mr. Gartner had lived in Rockville, and for the past 30 years, in Washington Grove.

He started work with the Main Post Office in Washington in 1942, and later was transferred to the Rockville Post Office, where he was a money order clerk until 195@r

He served with the Marine Corps for three years in World War II, seeing duty in the Pacific.

Mr. Gartner was a member of the Argyle Country Club, where he won the club championship twice and the senior championship seven times. He belonged to the Senior Southern Golf Association and the Free State Seniors Golf Association of Maryland.

He is survived by his wife, Marietta, of the home; a son, William E. Jr., of Kemptown; a daughter, Joan G. Broomall, of Damascus; four sisters, Margaret Magers, of Silver Spring, Lois Crown, of Gaithersburg, Katherine Mocarsky, of Damascus, and Irene Monard, of Rockville; a brother, James O., of Rockville, and four grandchildren.