Elisabeth S. Riley, 75, a technical editor who worked for a number of firms in the Washington area and elsewhere and for the federal government, died of cancer Sept. 21 at her home in Silver Spring.

Mrs. Riley was born in Washington and graduated from the old Central High School. She attended Goucher College and graduated from the old Wilson Teachers College. As a young woman, she taught in Arlington for two years.

In 1949, she went to work for the Atomic Energy Commission, where she helped set up a library for classified material. From 1955 to 1958, she was a document control officer on the disarmament staff at the White House. From 1960 to 1969, she lived in Albuquerque, N.M., and then in Blue Bell, Pa., where she was a technical editor with the Univac Co.

Mrs. Riley returned here in 1969 and became a technical editor with the Informatics Information Systems Co. In 1980, she went to work for the Planning Research Corp. in Linthicum Heights, Md., and retired later that year.

Her husband, Dr. Francis A. Riley, died in l968.

Survivors include two daughters, Margaret R. Caton of Wayne, Pa., and Frances R. Carson of Laurel, and four grandchildren.