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.
The movie was deliberately filmed in black and white in an attempt to disguise Clark Gable's age and weight.
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).
Many critics questioned why Erica would have been treating Gannon as a young journalistic prodigy when he is clearly close to retirement age.