The movie was deliberately filmed in black and white in an attempt to disguise Clark Gable's age and weight.
Cary Grant and James Stewart both turned down the role of James Gannon because they knew they were too old for the part. However, Clark Gable, who did play the part, was older than either of them.
Jim Gannon is shown defiantly smoking after being asked not to. In real life Clark Gable smoked four packs of cigarettes a day.
Although most critics felt that Clark Gable was badly miscast due to his age, his performance was judged good enough for Burt Lancaster to cast him as a dying submarine captain in Run Silent Run Deep (1958).
The character of Jim Gannon originally was supposed to be a reporter. However, when veteran star Clark Gable was cast, it was decided to make him an editor instead.