Klec

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)