- Bent Mejding
- Svend Viltorft
- Asbjørn Andersen
- Prof. Otto Martens
- Povl Wøldike
- Dr. Peter Dalby
- Ann Smyrner
- Lise Martens
- Mimi Heinrich
- Karen Martens
- Dirch Passer
- Petersen
- Marlies Behrens
- Connie Miller (American version)
- Carl Ottosen
- Gen. Mark Grayson
- Ole Wisborg
- Capt. Einer Brandt
- Birthe Wilke
- Self - Nightclub Singer
- Mogens Brandt
- Police Chief Hassing
- Kjeld Petersen
- Police Officer Olsen
- Jens Due
- Journalist
- May Reimers
- Badegæst
- Jørgen Blaksted
- Naval Officer
- Robert Cornthwaite
- Man
- Børge Møller Grimstrup
- Danish Farmer
- Egon Gydesen
- Danish Soldier
- Knud Hallest
- Naval Officer
- Svend Johansen
- Naval Officer
- Benny Juhlin
- Danish Soldier
- Dirk Melchior
- Farmer Eaten by Reptilicus
- Bodil Miller
- Connie Miller (Danish version)
- Hardy Rafn
- (uncredited)
- Martin Stander
- (uncredited)
- Alex Suhr
- Alex - Drilling Crew
- Poul Thomsen
- Orlogskaptajn
- Claus Toksvig
- Self - Narrator
- Bent Vejlby
- Danish Soldier
- Alfred Wilken
- (uncredited)
