He was 86. Mr. Zwerdling founded Back Stage in 1960 with Ira Eaker. Both men had worked at the publication Show Business. (Ad man Eaker died in 2002.)

Mr. Zwerdling was born in Brooklyn. His father was in the wholesale produce business. He was a child actor with the Players Guild of Manhattan. After serving in the U.S. Air Force Special Services in World War II, 1942-45, during which time he produced and directed 95 shows for servicemen, he was producer-director for the American Players in Zurich, Switzerland, and assistant to the director of the Zurich State Theatre (1946-47). He was also director of the Kansas City Resident Theatre (1947-48).

Between 1948-60, Mr. Zwerdling worked for eight theatrical periodicals, and his writing appeared in many newspapers. He also wrote plays. He was a writer and editor at Show Business before he started Back Stage.

Back Stage — which was sold to Billboard Publications in 1986 — has a current circulation of 32,000, a spinoff publication (Back Stage West, based in Los Angeles) and a website.

Mr. Zwerdling, who retired to a farm, is survived by daughters Sherry Zwerdling of Key West, FL, and Jan Heyes of Topanga Canyon, CA; son Gary Zwerdling of Rosendale; and a grandson. His wife since 1946, Shirley M. Zwerdling, died in 2008.