Jerome O. Kilmartin, 78, a mapping official with the U.S. Geological Survey for more than 50 years before his retirement in 1970, died Saturday at Arlington Hospital. He suffered from cancer.

His last position was that of chief of the survey's map information office. He had joined the survey in 1918 as a field topographer.

Mr. Kilmartin was a pioneer in field mapping in remote areas of the Hawaiian Islands, and had worked on mapping projects in Alaska, Puerto Rico and the eastern United States.

He assisted the Carnegie Institution in archeological exploration of ancient Mayan cities in Guatemala and the Yucatan of Mexico.

In 1958, Mr. Kilmartin became the first executive secretary for domestic names with the interdepartmental U.S. Board on Geographic Names. He was a deputy member of the board, representing the Interior Department from 1967 through 1969. He also was secretary to the Committee on Topographic Maps and Aerophotogrammetry of the Pan American Institute of Geography and History from 1954 to 1965.

He received the Interior Department's Distinguished Service Award in 1971.

Mr. Kilmartin was born in Petersburg, Va., and attended Virginia Polytechnic Institute in Blacksburg.

He was a former secretary and treasurer of the Washington group of the Explorers Club and belonged to the Cosmos Club.

He is survived by his wife, Doris, of the home in Arlington; two sisters, Mrs. S. G. Ridley and Mrs. J. W. Broderick, and a brother, P. M. Kilmartin, all of Waverly, Va., and another brother, Robert W., of Webster, Mass.

The family suggests that expressions of sympathy may be in the form of contributions to the Children's Home Society of Virginia in Richmond.