Leon Cherner, 75, a prominent automobile dealer in the Washington area who was active in church and service organizations, died Friday at the Fernwood nursing home in Bethesda.He had cancer.

Mr. Cherner was president of the Cherner Motor Co., a Ford dealership, and the Cherner Shirlington Motor Co., a Lincoln-Mercury outlet, until his retirement in 1973 for reasons of health. Both firms were dissolved at that time.

He was born in Russia and came to the United States when he was about 6 years old. His family settled in Washington and he remained in this area.

In the 1920s, Mr. Cherner worked in the retail grocery business. He became interested in selling automobiles and was a part-owner of two dealerships by the early 1930s. In 1935, he joined a brother, Joseph, in the Cherner Motor Co., which at that time was located at 1781 Florida Ave. NW.

The firm acquired a second site in Shirlington in 1946. Eventually, both the Ford and Lincoln-Mercury dealerships were located in Shirlington. Mr. Cherner became president of the companies in 1956.

In addition to his work, Mr. Cherner was active in B'nai B'rith, the Jewish service organization. He was a member of the executive committee of the United Jewish Appeal and a trustee and president of Tifereth Israel Congregation.

In 1966, he received the Humanitarianism Award from B'nai B'rith. The award was presented by Lee Iacoca, who later became president of the Ford Motor Co.

Mr. Cherner was a board member of the United Bank of Virginia and the Shirlington Trust Co. He was an advisory board member of American Security and Trust Co.

He also was a member of the Metropolitan Washington Board of Trade, the Variety Club and the Advertising Club of Washington.

Survivors include his wife, Esther, of the home in Washington; two daughters, Peggy Zeitler, of Munich, Germany, and Helen Rees, of Boston; a son, Harvey, of Bethesda; two sisters, Mrs. Henry Gertler, of Bethesda, and Luba Lapkoff, of Silver Spring; two brothers, Henry, of Arlington, and Reuben, of Washington, and eight grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society Research Fund, or to B'nai B'rith Youth Services. CAPTION: Picture, LEON CHERNER