After completing his civil service, he then took acting lessons from 1981 to 1984 at the Hamburg drama school stage studio with Hedi Höpfner (another actress) and then joined a festival engagement at the Theater Bremen.

He was initially as assistant to Commissar Flemming (Martin Lüttge) in Düsseldorf, later he was commissary leader with his colleague 'Freddy Schenk' (Dietmar Bär) in Cologne.

In 2007, he played in the ARD television drama Einfache Leute (Simple people) alongside Barbara Auer, as a family man hiding his homosexuality.

In October 2000, Klaus J. Behrendt and Dietmar Bär received for their roles in Tatort the German Television Award for Best Series Actor of 1999.

Then in 2007 episode Mine Game was nominated for the Marler Media Prize Human Rights award (by the German section of Amnesty International).

[6] In 2011, he with the castmates Jan Josef Liefers, Axel Prahl and Dietmar Bär received a 1Live crown (German music award).