Der geheimnisvolle Killer

Nude per l'assassino (English: Strip Nude for Your Killer) is a 1975 giallo film directed by Andrea Bianchi. Written by Massimo Felisatti, the film stars Nino Castelnuovo, Edwige Fenech and Solvi Stubing, and features music by Berto Pisano. Nude per l'assassino has received mixed to negative reviews from critics.

After a model dies while undergoing an illegal abortion, a killer disguised in a motorcycle helmet tracks down and kills the doctor involved. Several models and photographers working at the same agency as the dead girl are also murdered, leading two surviving photographers to fear for their lives as they try to track down the killer.

Nude per l'assassino is one of several collaborations between Bianchi, Felisatti and cinematographer Franco Delli Colli. The film has been described as a formulaic giallo thriller, and has been cited as an influence on the development of the American slasher film genre.