Boris Runge

Lyova Prokushev

Dagmara Deringer

Lidochka

Yekaterina Derevshchikova

Katya

Anatoliy Ignatyev

Seryozha

Vera Altayskaya

Marusya Ivanova, pioneer leader

Pyotr Savin

Vladimir Vishnyakov, teacher

Lev Potyomkin

Arkadiy's father

Nina Rusinova

Arkadiy's mother

Andrei Tutyshkin

School headmaster

Elena Maksimova

Vitya Surikov's mother

Anatoli Goryunov

Doctor (uncredited)

Aleksandr Sashin-Nikolsky

Friend of Surikov's mother