Oskar Werner and Richard Basehart did most of their own stunt work, including jumping in and swimming the fast currents of the Rhine river on location in Germany.
Based on a true story. Towards the end of the war, Allied military intelligence services did recruit, train and utilize German POWs to return to Germany and spy for them.
December 8th, 1944: the date on which Karl Maurer (Werner) is captured in the film, was in real life the actual date on which Oskar Werner deserted from the Wehrmacht.
Many felt that the reason why Decision Before Dawn picked up a surprise Best Film nomination at the Academy Awards was because its producer Darryl F. Zanuck had pushed it with an expensive 12 page glossy insert in all the trade magazines.
One of the first films after World War II to portray the German people - outside of the Nazi regime - in a sympathetic light.
Since the instigation of five Best Picture nominees for the Academy Awards in 1944, this was the first Best Film nominee to only be nominated in one other category. The next instance of this occurred in 1994 when Four Weddings and a Funeral only picked up two nominations (including Best Film).
The producers and director Anatole Litvak chose to film the movie on location in postwar Germany because of its authentic background - many of the country's large cities still had areas that had been bombed into rubble and not been rebuilt yet, and there was a lot of actual WW II German military equipment - tanks, rifles, uniforms, etc. - still available.