Kaiser made his stage début in 1941 at the Stadtheater in Jihlava, Czechoslovakia, when that country was occupied by Germany.Kaiser starred as Mack the Knife in Brecht and Weill's The Threepenny Opera in more than 450 times.Kaiser had acted in films since the Second World War, including roles in Wolfgang Staudte's Die Geschichte vom kleinen Muck (1953),[2] Kurt Maetzig's Ernst Thälmann, Sohn Seiner Klasse (1954),[3] Martin Hellberg's Thomas Müntzer and Peter Palitzsch and Manfred Wekwerth's film of Brecht's play, Mutter Courage und ihre Kinder (1961).[8] From 1969 Kaiser concentrated his career on screen acting, including Peter Zadek's 1973 version of Kleiner Mann – was nun?He was distressed at its collapse in 1989, its corruption that came to light after its fall and German reunification, and the return of capitalism and mass unemployment to eastern Germany from 1989 onwards.