Robert W. Cotton, 57, a partner in the consulting engineering firm of Cotton and Wareham since 1973, died of a pulmonary embolism Thursday at Sibley Memorial Hospital.

Born in Des Moines, Iowa, he came to the Washington area as a child. He later attended Catholic University and served with the Army in the Pacific during World War II.

Mr. Cotton was first employed by the consulting engineering firm of J. F. Hoppe in Washington. From 1949 to 1957, he was with Karsunky, Weller and Gooch. He then was a partner in Cotton and Harris for 14 years before forming Cotton and Wareham.

He was responsible for the mechanical design of several buildings at Catholic University, including the Hartke Theater, and at Georgetown University and Canal Square in Georgetown. He also had worked on the Watergate and Cairo apartment projects.

Mr. Cotton was a past president of the Consulting Engineers Council of Metropolitan Washington and the Washington Building Congress. He was a member of the D.C. Society of Professional Engineers and Cheverly Post No. 108 of the American Legion. He was a former commodore of the Chesapeake Yacht Club in Shady Side, Md.

He is survived by his wife, Margaret, of the home in Rockville; two daughters, Marielaine Mowell, of Rockville, and Jeanette Williams, of Albany, Ga.; two sons, Robert W. Jr., of Greenville, Tom and Gregory, of Herald Harbor Md.; two stepchildren, James Mutchler, of Los Angeles, and Patricia Mutchler, of Rockville; his mother Irene Cotton, of Washington; three brothers, Richard, of Glendale, Calif., James, of Springfield, Va., and Paul, of Potomac, and six grandchildren.