Werner Klemperer, Howard Caine, Leon Askin, and John Banner were all Jewish. All of them also served in the U.S. Armed Forces during World War II. Klemperer was born in Cologne, Germany, and Banner and Askin were both born in Vienna, Austria. The three of them immigrated to the United States after fleeing the Nazi regime.
Werner Klemperer only agreed to play Colonel Klink once he was assured (by the show's creator) that Klink would never succeed in his schemes.
The leather jacket that Bob Crane wore on this show, was originally worn by Frank Sinatra in Von Ryan's Express (1965). Vito Scotti who played Major Bonacelli in an episode played the train engineer in "Von Ryan's Express." The same jacket was also worn by Greg Kinnear in Auto Focus (2002) a Bob Crane film biography. It is currently on display at the Liberty Aviation Museum, Port Clinton, Ohio.
Early in production planning, it was decided to make it always be winter, with snow on the ground, and frost on the windows. This was to prevent problems with continuity, and to allow the episodes to be shown in any order (it also makes prison life seem bleaker, and being winter adds even more of a menace whenever Klink or Schultz are being threatened with being sent to the Russian front). Since much of the filming was done in the summer, the cast members had to wear coats and act cold, even when the temperature was over ninety degrees Fahrenheit (thirty-two degrees Celsius).