Akihiko Hirata
Dr. Serizawa
Takashi Shimura
Dr. Yamane
Emilio Cigoli
Steve Martin (voice)
Rita Savagnone
Emiko Yamane (voice)
Giuseppe Rinaldi
Ogata (voice)
Vittorio Cramer
George Lawrence (voice) (as Vittorio Kramer)
Pino Locchi
Security Officer Tomo Iwanaga (voice)
Sachio Sakai
Hagiwara (uncredited)
Fuyuki Murakami
Dr. Tabata (uncredited)
Ren Yamamoto
Seiji (uncredited)
Toyoaki Suzuki
Shinkichi (uncredited)
Tadashi Okabe
Dr. Tabata's Assistant (uncredited)
Toranosuke Ogawa
President of Company (uncredited)
Frank Iwanaga
Security Officer Tomo Iwanaga (uncredited)
Mikel Conrad
George Lawrence (uncredited)
Kokuten Kōdō
The Old Fisherman (uncredited)
Kenji Sahara
Man on Boat (uncredited)
Haruo Nakajima
Godzilla (uncredited)
Katsumi Tezuka
Godzilla (uncredited)
