Jan Tříska
— Jan Svozil
Jana Hliňáková
Jaroslav Rava
— Stanislav Hradecký
Jana Hlaváčková
— Vlasta Martínková
Gabriela Wilhelmová
— Hana
Zdena Herfortová
— Eva Svozilová
Oldřich Vykypěl
— ROH chairman
Oldřich Slavík
— Jaroslav Stehlík (uncredited)
Jiří Hanák
— Miroslav Janoušek (uncredited)
Vilém Pfeiffer
— Bartoněk (uncredited)
Jiří Dušek
— Zdražil (uncredited)
Milan Pásek
— Institute director (uncredited)
Karel Adam
— Department manager (uncredited)
Helena Trýbová
— Scientist (uncredited)
Vladimír Pavlar
— Doc. Rozehnal (uncredited)
Bohumil Slezáček
— Professor (uncredited)
Arnošt Navrátil
— Doctor (uncredited)
Sylvie Nitrová
— Nurse (uncredited)
Marcela Dürrová
— Laboratory assistant (uncredited)
Miroslav Donutil
— Assistant (uncredited)
Milan Kročil
— Assistant (uncredited)
Zdeněk Maryška
— Assistant (uncredited)
Zdeněk Dryšl
— Houseman (uncredited)
Jana Gazdíková
— Secretary (uncredited)
Blažena Rýznarová
— Official (uncredited)
Markéta Rauschgoldová
— Canteen assistant (uncredited)