Samuel C. Cohn, 68, retired senior partner of an accounting firm here, died Wednesday at George Washington University Hospital after suffering an aneurysm.

Formerly a partner in the accounting firm of Burke, Landsberg and Gerber in Baltimore, he opened their Washington office in 1943. He became managing partner when that branch office became a separate firm here.

In 1968, Mr. Cohn merged his accounting firm with J. K. Lasser here. In 1977, that firm was merged with Touche Ross and Co. and he was made a senior partner, a position he held until retiring last August.

Mr. Cohn was born in Baltimore. He was a graduate of the University of Baltimore and was a certified public accountant.

Since his retirement, he had been doing volunteer work with the Service Corps. of Retired Executives and with the National Jewish Hospital in Denver. He lived in Washington.

Mr. Cohn was a member of Adas Israel Synagogue, the Men's Club of the Hebrew Home of Greater Washington and the Samuel Gompers Lodge of the Masons.

He is survived by his wife, Anne, of Washington; two daughters, Harriet Legum, of Baltimore, and Susan Cohn, of Bethesda; a brother, Benjamin, of Washington; a sister, Evelyn Cohn, of Baltimore, and two grand-children. o

The family suggests that expressions of sympathy be in the form of contributions to the National Jewish Hospital.