Born to German parents in the US, he didn't realize he had US
citizenship until he applied for a visa to move there in 1933.
When he took part in Anti-Nazi films he used the pseudonym John Voigt in order to protect the life of his father who still lived in Berlin.
After World War II the demand for German actors diminished and Wolfgang Zilzer concentrated to the theater. Occasionally he appeared on stage in Germany but returned to the USA over and over again.
After his wife had attracted some attention in 1976 in the thriller The Marathon Man (with Dustin Hoffman and Laurence Olivier ), the two came back to small film roles in Hollywood in old age.
The last years of his life he spent in Berlin where he died on the 26th of June 1991.