 | Michael Rennie | | Lord John Roxton |
| Jill St. John | | Jennifer Holmes |
| David Hedison | | Ed Malone |
| Claude Rains | | Prof. George Edward Challenger |
| Fernando Lamas | | Manuel Gomez |
| Richard Haydn | | Prof. Summerlee |
| Ray Stricklyn | | David Holmes |
| Jay Novello | | Costa |
| Vitina Marcus | | Native Girl |
| Ian Wolfe | | Burton White |
| Al Bain | | Man at Airport |
| Ross Brown | | Airport Attendant |
| Colin Campbell | | Prof. Waldron |
| Fred Cavens | | French Member of Zoological Institute Forum |
| Larry Chance | | Indian Chief |
| Phyllis Coghlan | | British Member of Zoological Institute Forum |
| Paul Cristo | | Guest at Zoological Institute Forum |
| Anne Dore | | Member of Zoological Institute Forum |
| Alex Finlayson | | Reporter |
| Bess Flowers | | Guest at Zoological Institute Forum |
| Peter Fontaine | | Airport Attendant |
| Don Forbes | | TV Announcer |
| John Graham | | Stuart Holmes |
| Sam Harris | | Man at Airport / Guest at Zoological Institute Forum |
| Ivo Henderson | | British Member of Zoological Institute Forum |
| George Holmes | | Guest at Zoological Institute Forum |
| Stuart Holmes | | Zoological Institute Professor on Stage |
| Freda Jones | | Guest at Zoological Institute Forum |
| Kenner G. Kemp | | Guest at Zoological Institute Forum |
| Harold Miller | | Guest at Zoological Institute Forum |
| Sándor Naszódy | | German Member of Zoological Institute Forum |
| George Pelling | | Reporter |
| Murray Pollack | | Guest at Zoological Institute Forum |
| Ruggero Romor | | Italian Member of Zoological Institute Forum |
| Brian Roper | | British Member of Zoological Institute Forum |
| Cosmo Sardo | | Guest at Zoological Institute Form |
| Owen Song | | Guest at Zoological Institute Forum |
| Jacqueline Squire | | British Member of Zoological Institute Forum |
| Bert Stevens | | Reporter at Airport |
| Gilchrist Stuart | | Reporter |
