 | Raymond Burr als Steve Martin |
 | Akira Takarada als Ogata |
 | Akihiko Hirata als Dr. Serizawa |
 | Takashi Shimura als Dr. Yamane |
 | Momoko Kôchi als Emiko |
 | Frank Iwanaga als Security Officer (uncredited) |
 | Sachio Sakai als Hagiwara (uncredited) |
 | Fuyuki Murakami als Dr. Tabata (uncredited) |
 | Ren Yamamoto als Seiji (uncredited) |
 | Toyoaki Suzuki als Shinkichi (uncredited) |
 | Tadashi Okabe als Dr. Tabata's Assistant (uncredited) |
 | Toranosuke Ogawa als President of Company (uncredited) |
 | Mikel Conrad als George Lawrence (uncredited) |
 | Kenji Sahara als Man on Boat (uncredited) |
 | Haruo Nakajima als Godzilla (uncredited) |
 | Katsumi Tezuka als Godzilla (uncredited) |
 | Emilio Cigoli als Steve Martin (voice) |
 | Rita Savagnone als Emiko (voice) |
 | Giuseppe Rinaldi als Ogata (voice) |
| Vittorio Cramer als George Lawrence (voice) (as Vittorio Kramer) |
 | Pino Locchi als Security Officer (voice) |
| Luigi Cozzi | Director |
| Ishirō Honda | Director |
| Akira Ifukube | Original Music Composer |
| Alberto Moro | Editor |
| Fabio Frizzi | Original Music Composer |
| Tomoyuki Tanaka | Producer |
| Franco Bixio | Original Music Composer |
| Vince Tempera | Original Music Composer |
| Renato Barbieri | Executive Producer |
| Terry O. Morse | Director |
| Luigi Cozzi | Executive Producer |
| Guy Roe | Director of Photography |
| Masao Tamai | Director of Photography |
| Ishirō Honda | Author |
| Tomoyuki Tanaka | Story |
| Eiji Tsuburaya | Story |
| Takeo Murata | Screenplay |
| Shigeru Kayama | Novel |
| Al C. Ward | Screenplay |
| Terry O. Morse | Story |
| Eiji Tsuburaya | Visual Effects |
| Sadao Iizuka | Visual Effects |
| Fuminori Ōhashi | Visual Effects |
| Hiroshi Mukoyama | Visual Effects |
| Armando Valcauda | Colorist |
| Shigeru Kayama | Lyricist |
| Eiji Tsuburaya | Special Effects |
| Teizô Toshimitsu | Costume Designer |
| Satoru Chûko | Art Direction |
| Takeo Kita | Art Direction |
| Takeo Kita | Production Design |
| Satoru Chûko | Production Design |
| George R. Rohrs | Sound Effects |
| Ishirō Honda | Screenplay |
| Shigeru Kayama | Original Story |
| Armando Valcauda | Visual Effects |
| Franco Foco | Consulting Producer |
| Giovanni Mongini | Consulting Producer |
| Luigi Valerio | Consulting Producer |
| Giuseppe Festino | Graphic Designer |
| Lillo Capoano | Script Supervisor |
| Akira Watanabe | Visual Effects |
| Kuichirô Kishida | Visual Effects |
