 Dominique SandaLou Andreas Salomé | Lou Andreas Salomé |
 Erland JosephsonFriedrich Nietzsche | Friedrich Nietzsche |
 Robert PowellPaul Rée | Paul Rée |
 Virna LisiElizabeth Nietzsche | Elizabeth Nietzsche |
 Michael DegenKarl Andreas | Karl Andreas |
 Elisa CeganiFranziska Nietzsche | Franziska Nietzsche |
 Umberto OrsiniBernard Foester | Bernard Foester |
 Philippe LeroyPeter Gast | Peter Gast |
 Carmen ScarpittaMalvida | Malvida |
 Nicoletta MachiavelliAmanda | Amanda |
 Amadeo AmodioDr. Dulcamara | Dr. Dulcamara |
 Elisabeth WienerGreta | Greta |
 Roberto BruniJulius Longbehn | Julius Longbehn |
 Mircha CarvenWolfgang | Wolfgang |
 Clara AlgrantiTeresa | Teresa |
| RRobert José PomperYoung Venetian Gondolier | Young Venetian Gondolier |
 Renato ScarpaPsychiatrist | Psychiatrist |
 Francesca MuzioMaria | Maria |
 Anita HöferProstitute at Station | Prostitute at Station |
| HHeinz KreugerUniversity Rector | University Rector |
 Vinicio DiamantiNot listed | Not listed |
| HHélène BeaucourMadam at Colonia Bordello (uncredited) | Madam at Colonia Bordello (uncredited) |
 Lars BlochGerman Friend (uncredited) | German Friend (uncredited) |
 Ritza BrownYoung Sicilian Prostitute (uncredited) | Young Sicilian Prostitute (uncredited) |
 Guido CernigliaGuest in Malvida's House (uncredited) | Guest in Malvida's House (uncredited) |
| CCarlo ColomboBonnet (uncredited) | Bonnet (uncredited) |
 Clara ColosimoTrude (uncredited) | Trude (uncredited) |
 Geoffrey CoplestonGuest in Malvida House (uncredited) | Guest in Malvida House (uncredited) |
 Elvira CorteseMaid (uncredited) | Maid (uncredited) |
 Catharina DahlinProstitute (uncredited) | Prostitute (uncredited) |
