Between 1916 and 1924, Werich attended "reálné gymnasium" (equivalent to high school) in Křemencova Street in Prague (where his future business partner, Jiří Voskovec, also studied).

The trio's work took inspiration from Dada, with its love of the absurd, a reaction against bourgeois values and the horrors of World War I.

With his new business partner Miroslav Horníček at his side, he re-staged many of the plays he had created with Voskovec in the 1930s but set them in the political content specific to the time.

Jan Werich appeared in such films as Byl jednou jeden král (English: Once Upon a Time There Was a King), which was released in 1955, and made many political compromises to appease the Communist censors.

Werich was originally cast by producer Harry Saltzman to play Ernst Stavro Blofeld in the 1967 James Bond film You Only Live Twice.