Ralph K. Hoitsma, 79, the warden-emeritus of St. Mark's Episcopal Church on Capitol Hill and a businessman and former government official, died Jan. 6 at George Washington University Hospital after a heart attack.

Mr. Hoitsma was born in Guernsey, Wyo., and and attended the University of Wyoming. He transferred to Colgate University in Hamilton, N.Y., where he graduated in 1926.

For most of his professional career, Mr. Hoitsma was a personnel and training officer with national oil companies. During World War II, he was assistant director of civilian personnel in the Office of the Secretary of War. He worked for Standard Oil of Ohio until 1954, when he came to Washington. He had managed his investments since then.

Mr. Hoitsma moved to Capitol Hill in 1959, and in 1961, after a heart attack, he became involved in St. Mark's Church, then a decaying inner-city parish. Over the next two decades, he raised funds and helped organize the renovation of the building and revitalization of the congregation. He served as junior and senior warden and then was elected warden emeritus. The church's tower was dedicated in his honor.

He is survived by his wife, the former Muriel Cutten, of Washington; two sons, Derrik, of New York City, and Kinmont, of San Francisco; a sister, Kathryn Olson of Atlanta; six grandchildren, and a great-grandchild.