Also Known As:- El gato de las nueve colas
- The Cat o' Nine Tails
- A kilencfarkú macska
- Cat o' Nine Tails
- Døden leker blindebukk
- De nio heta spåren
- Die neunschwänzige Katze
- Dokuz kuyruklu kedi
- Hiipivä kauhu
- Kot o dziesieciu ogonach
- Le chat à neuf queues
- O Gato das Sete Vidas Porugal
- O Gato de Nove Caudas
- O gatos me tis 9 oures
- Smygande skräck
- Dario Argento
- Dario Argento
- Luigi Collo
- Dardano Sacchetti
- Bryan Edgar Wallace
- James Franciscus ... Carlo Giordani
- Karl Malden ... Franco Arno
- Catherine Spaak ... Anna Terzi
- Pier Paolo Capponi ... Police Supt. Spini
- Horst Frank ... Dr. Braun
- Rada Rassimov ... Bianca Merusi
- Aldo Reggiani ... Dr. Casoni
- Carlo Alighiero ... Dr. Calabresi
- Vittorio Congia ... Righetto (cameraman)
- Ugo Fangareggi ... Gigi the Loser
- Tom Felleghy ... Dr. Esson
- Emilio Marchesini ... Dr. Mombelli
- Fulvio Mingozzi ... Spimi's man
- Corrado Olmi ... Morsella
- Pino Patti ... Barber
- Umberto Raho ... Manuel's ex-lover
- Jacques Stany ... Prof. Manera
- Stefano Oppedisano ... Taxi driver
- Ada Pometti ... Telephone operator
- Walter Pinelli
- Sascha Helwin (as Sacha Helwin)
- Marie Louise Sinclair ... Film starlet (as Marie Luise Zetha)
- Martial Boschero
- Cinzia De Carolis ... Lori
- Werner Pochath ... Manuel
- Tino Carraro ... Prof. Fulvio Terzi
- Aristide Caporale ... Smoker in the Billiard Hall
- Giovanni Di Benedetto ... Chief of Police Salmi
- Margherita Horowitz ... Lori's Babysitter
- Giuseppe Marrocco ... Man at Table in the Saint Peter's Club
- Gennarino Pappagalli ... Man in the Terzi's Institute
- Aldo Parenti ...
- Franco Ukmar ... Policeman - Speaks with Morsella About Food
