Starting in 1955 he began producing movies, first with his company "Urania": The films The Man in the Black Derby and The Model Husband starring Swiss comedian Walter Roderer turned into big successes.
Movies that he either directed or produced, often using pseudonyms such "Michael Thomas" or "Manfred Gregor" under the umbrella of newly "Elite-Film" (later: "Ascot Film GmbH").
Film such as Love Letters of a Portuguese Nun or Jack the Ripper with performances by Klaus Kinski were praised by industry friends and fans such as Joe Dante and Quentin Tarantino who once called Erwin the "Swiss Roger Corman".
The Story of Piera produced by him and directed by Marco Ferreri, starring Isabelle Huppert and Marcello Mastroianni, may not have been a commercially comparable success to Erwin's other productions but it turned into a huge hit at the festivals, and Hanna Schygulla received the "Golden Palm" in Cannes for her performance.
Emphasized by a gigantic marketing campaign (including an ecstatic Klaus Kinski dominating the promo tour) he released in the mid-80s the "mercenary trilogy" consisting of Code Name: Wild Geese, Commando Leopard and The Commander [de] on the big screen, the cast included Klaus Kinski, Ernest Borgnine, and Lee Van Cleef.