Jerschke studied acting as a young man, landing his first movie part in the 1938 Nazi propaganda film Pour le Mérite, in a bit as a young adjutant. Postwar, he found more success performing in revues and as a movie character actor. He featured in several of the Edgar Wallace mystery films, first as the voice of a radio newscaster in Der Frosch mit der Maske (1959, based on The Fellowship of the Frog), and then on-camera (in parts such as lawyers and coroners) in The Dead Eyes of London (1961), The Forger of London (1961), and Secret of the Red Orchid (1962). TV included appearances on Percy Stuart and Tatort.