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.
| Directing | Dario Argento | Director |
| Writing | Dario Argento | Story |
| Writing | Luigi Cozzi | Story |
| Writing | Mario Foglietti | Story |
| Writing | Dario Argento | Screenplay |
| Camera | Franco Di Giacomo | Director of Photography |
| Production | Salvatore Argento | Producer |
| Sound | Ennio Morricone | Original Music Composer |
| Art | Enrico Sabbatini | Production Design |
| Costume & Make-Up | Paolo Borselli | Hairstylist |
| Editing | Françoise Bonnot | Editor |
| Costume & Make-Up | Giuliano Laurenti | Makeup Artist |
| Crew | Carlo Rambaldi | Special Effects |
| Sound | Massimo Anzellotti | Sound Effects Editor |
| Sound | Eugenio Fiori | Boom Operator |
| Crew | Dino Galiano | Special Effects |
| Camera | Roberto Carnevali | Still Photographer |
| Production | Carlo Du Bois | Administration |
| Art | Giovanni Viti | Assistant Art Director |
| Sound | Franco Bassi | Sound Mixer |
| Camera | Umberto Dessena | Grip |
| Costume & Make-Up | Giovanni Viti | Wardrobe Assistant |
| Costume & Make-Up | Giovanni Morosi | Assistant Makeup Artist |
| Camera | Giuseppe Lanci | Camera Operator |
| Sound | Edda Dell'Orso | Musician |
| Lighting | Orazio Sinacore | Electrician |
| Art | Mario Grilli | Decorator |
| Camera | Mario Boccanegra | Grip |
| Camera | Roberto Forges Davanzati | Assistant Camera |
| Art | Franco Pedacchia | Set Dresser |
| Lighting | Franco Gubiotti | Electrician |
| Camera | Gianfranco Transunto | Assistant Camera |
| Editing | Bruno Bianchini | Assistant Editor |
| Production | Roberta Leoni | Production Secretary |
| Sound | Bruno Nicolai | Conductor |
| Directing | Roberto Pariante | Assistant Director |
| Lighting | Anteo Pacini | Electrician |
| Directing | Patrizia Zulini | Script Supervisor |
| Camera | Fernando Monti | Grip |
| Production | Angelo Iacono | Production Manager |
| Lighting | Valerio Garzia | Gaffer |
| Costume & Make-Up | Mina Manes | Tailor |
| Production | Carlo Cucchi | Production Secretary |
| Art | Giuseppe Ciccocioppo | Props |
| Camera | Mauro Marchetti | Assistant Camera |
| Costume & Make-Up | Massimo Lentini | Assistant Costume Designer |
| Sound | Mario Ronchetti | Sound Engineer |
| Camera | Gastone Coppa | Key Grip |
| Lighting | Ennio Mancini | Electrician |
| Editing | Sergio Fraticelli | Assistant Editor |
| Sound | Luciano Anzellotti | Sound Effects |
| Production | Giuseppe Mangogna | Unit Manager |
| Directing | Luigi Cozzi | Assistant Director |
