At one point 6-months-old Jeff Bridges - playing the infant son (Jane Greer) is supposed to be holding in the train station - was supposed to cry. To get him to cry, Jeff's mother suggested they pinch him. (Source is Jeff Bridges interview in the Nerdist podcast posted 15 July, 2013)
Feature film debut of Jeff Bridges. His older brother, Beau Bridges, and their mother, Dorothy Dean Bridges, also appear in the film. Jeff would co-star once more with Jane Greer 31 years later in Against All Odds (1984).
When this film was made, Howard Hughes owned both RKO, which produced it, and TWA, whose logo is featured prominently on the airplane in the airport sequence.
According to studio records, this film flopped at the box office, resulting in a loss for RKO of $315,000 ($3.1M in 2017).
It is well known now that the infant child that Jane Greer is holding in the railroad station scene is a 4-month-old Jeff Bridges. What you may not know is that when Greer and Bridges appeared together in Against All Odds (1984), the1984 remake of Out of the Past (1947) in which Greer also starred, neither remembered that they had shared the screen in that earlier scene. It was not until the filming of Against All Odds that Greer and Bridges were informed by the Bridges' family members that he was that 4-month-old child that she held in the railroad station scene in The Company She Keeps.