Roberto, de drummer van een rockgroep, krijgt regelmatig vreemde telefoontjes en wordt constant achtervolgd door een vreemde man. Hij probeert de man aan te spreken, maar het gesprek loopt uit in een handgemeen en Roberto steekt de man dood.
Nee, helaas is 4 mosche di velluto grigio nog niet beschikbaar op Netflix in Nederland.
| Writing | Mario Foglietti | Story |
| Writing | Dario Argento | Screenplay |
| Writing | Dario Argento | Story |
| Writing | Luigi Cozzi | Story |
| Directing | Dario Argento | Director |
| Camera | Franco Di Giacomo | Director of Photography |
| Production | Salvatore Argento | Producer |
| Costume & Make-Up | Paolo Borselli | Hairstylist |
| Art | Enrico Sabbatini | Production Design |
| Editing | Françoise Bonnot | Editor |
| Costume & Make-Up | Giuliano Laurenti | Makeup Artist |
| Sound | Ennio Morricone | Original Music Composer |
| Crew | Carlo Rambaldi | Special Effects |
| Sound | Mario Ronchetti | Sound Engineer |
| Camera | Gastone Coppa | Key Grip |
| Lighting | Ennio Mancini | Electrician |
| Sound | Bruno Nicolai | Conductor |
| Production | Angelo Iacono | Production Manager |
| Sound | Eugenio Fiori | Boom Operator |
| Costume & Make-Up | Mina Manes | Tailor |
| Editing | Bruno Bianchini | Assistant Editor |
| Directing | Roberto Pariante | Assistant Director |
| Lighting | Anteo Pacini | Electrician |
| Costume & Make-Up | Giovanni Viti | Wardrobe Assistant |
| Editing | Sergio Fraticelli | Assistant Editor |
| Sound | Massimo Anzellotti | Sound Effects Editor |
| Camera | Giuseppe Lanci | Camera Operator |
| Lighting | Orazio Sinacore | Electrician |
| Art | Giovanni Viti | Assistant Art Director |
| Sound | Franco Bassi | Sound Mixer |
| Camera | Gianfranco Transunto | Assistant Camera |
| Camera | Umberto Dessena | Grip |
| Camera | Fernando Monti | Grip |
| Art | Mario Grilli | Decorator |
| Directing | Patrizia Zulini | Script Supervisor |
| Costume & Make-Up | Giovanni Morosi | Assistant Makeup Artist |
| Art | Franco Pedacchia | Set Dresser |
| Camera | Mario Boccanegra | Grip |
| Costume & Make-Up | Massimo Lentini | Assistant Costume Designer |
| Sound | Edda Dell'Orso | Musician |
| Production | Roberta Leoni | Production Secretary |
| Art | Giuseppe Ciccocioppo | Props |
| Camera | Roberto Carnevali | Still Photographer |
| Camera | Mauro Marchetti | Assistant Camera |
| Camera | Roberto Forges Davanzati | Assistant Camera |
| Lighting | Franco Gubiotti | Electrician |
| Crew | Dino Galiano | Special Effects |
| Lighting | Valerio Garzia | Gaffer |
| Production | Carlo Cucchi | Production Secretary |
| Production | Carlo Du Bois | Administration |
| Sound | Luciano Anzellotti | Sound Effects |
| Production | Giuseppe Mangogna | Unit Manager |
