Raymond Burr
Steve Martin
Akira Takarada
Ogata
Akihiko Hirata
Dr. Serizawa
Takashi Shimura
Dr. Yamane
Momoko Kôchi
Emiko
Frank Iwanaga
Security Officer (uncredited)
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)
Mikel Conrad
George Lawrence (uncredited)
Kenji Sahara
Man on Boat (uncredited)
Haruo Nakajima
Godzilla (uncredited)
Katsumi Tezuka
Godzilla (uncredited)
Emilio Cigoli
Steve Martin (voice)
Rita Savagnone
Emiko (voice)
Giuseppe Rinaldi
Ogata (voice)
Vittorio Cramer
George Lawrence (voice) (as Vittorio Kramer)
Pino Locchi
Security Officer (voice)