Biederstaedt became famous in the 1950s with films such as Charley's aunt alongside Heinz Rühmann. For the film Fireworks he was in front of the camera with the then 16-year-old Romy Schneider. For his screen debut The Great Temptation (1951), he was awarded the Bundesfilmpreis for best young actor. In total he was seen in about 60 feature films.
In the 1960s and 1970s, Biederstaedt appeared in more than 200 television productions, including series such as Derrick , Die Schwarzwaldklinik and Der Alte.
Biederstaedt was also successful as a voice actor. He lent his voice to Hollywood greats such as Marlon Brando, Yves Montand and Paul Newman. He later moved to the theater and was still on the stage at a very old age.
In the past few years, things had become quiet around Biederstaedt after he contracted tongue cancer. Doctors had to amputate two thirds of his tongue. But he defeated cancer, said the son. Now he died shortly before his 92nd birthday.