Keenan Wynn and Harry Hayden were announced as cast members, but they did not appear in the film. Elliott Sullivan tested for the role of "General Philip Golikov" but he was not in the film.
A snow battle sequence was filmed in the Sierra Mountains of California in March 1943 with experts Eric Lundquist and Nils Larsen portraying Polish skiers, but the sequence was not used in the film.
Director Gregory Ratoff collapsed on the set on 29 June 1943; Laslo Benedek took over as director for the remainder of the principal photography and for the October 1943 retakes. It is not known who directed the retakes needed in September 1943.
This film was the subject of inquiry by the House Un-American Activities Committee (HUAC) in October 1947. Testimony as to the distortions of Soviet life presented in the film was provided by Ayn Rand, screenwriter and author of "The Fountainhead" and 'Atlas Shrugged". Rand was born in Russia, but left in 1926. Rand derided the depictions of Russian peasants who owned radios and had access to long distance telephones as well as showing a "traditional Russian wedding dance' with peasant women doing the Charleston with spiked heels in church.