In films since childhood in his native Germany, Kieling appeared in a few American films, notably in Alfred Hitchcock's Torn Curtain (1966), where he played Gromek, an East German agent brutally slain by Paul Newman's character.

He did much work on West German TV, including the first episode of Derrick ("Waldweg" [de], 1974).

During World War II, Kieling was conscripted into the German Army in 1942, where he was severely wounded and captured in 1945.

In October 1952, his wife Jola Jobst (ex-wife of German Luftwaffe ace Hermann Graf), whom he had married in 1950, committed suicide.

After defecting, he called the United States "the most dangerous enemy of humanity in the world today" with its "crimes against the Negro and the people of Vietnam".