In 1927, together with Werich, he joined the Osvobozené divadlo (Liberated Theater), which had been created two years earlier by members of the avant-garde Devětsil group, Jiří Frejka and Jindřich Honzl.

After disagreements led Frejka to leave the group in 1927, Honzl asked Voskovec and Werich, both law students who had created a sensation with their Vest Pocket Revue that year, to join the theatre.

Their performances began with the primary goal of evoking laughter through fantasy, but with the changing political situation in Germany their work became increasingly anti-fascist, which led to the closure of the Liberated Theater after the Munich Agreement in 1938.

After his return to the United States in 1950, Voskovec was detained at Ellis Island for eleven months for his alleged sympathy for Communism.

[citation needed] Although Voskovec lived in three countries and his maternal grandmother was French, he always maintained that "I am a born and bred Czech."

[citation needed] In 1975, he published the Czech spoken LP record "Relativně vzato", where he reflects on his life and world in general.

[citation needed] Voskovec starred on Broadway in 1961 along with Hal Holbrook in Do You Know the Milky Way by German playwright Karl Wittlinger.