Jack Nicholson and Danny DeVito previously appeared together in One Flew Over the Cuckoo's Nest (1975). That film also won awards for Best Picture, Best Director, Best Actress and Best Screenplay. Nicholson himself won an award for each film as well, but won Best Actor for the previous film, and Best Supporting Actor for this one.
James L. Brooks received a special gift at the end of production, to congratulate him for completing his first movie. This was a book of "Life in Hell" cartoons, drawn by Matt Groening. Brooks was so impressed with the comics that he asked Groening to create cartoon shorts for The Tracey Ullman Show (1987). This gave rise to The Simpsons.
While shooting the movie in Nebraska Debra Winger began dating the Governor Bob Kerrey; who told reporters, "she swept me off my foot," alluding to the fact that the lower part of one of his legs was amputated due to injuries sustained in his Medal of Honor action in Vietnam.
The character of Garrett Breedlove does not appear in the novel and was written specifically with Burt Reynolds in mind by writer-director James L. Brooks. Reynolds loved the script but was already committed to star in Stroker Ace (1983). Paul Newman and Harrison Ford turned down the role before Jack Nicholson signed on. Nicholson talked with a number of real astronauts while in Houston in preparation.
The MPAA originally gave this film an "R" rating due to strong language. It was reduced to "PG" on an appeal (the PG-13 rating did not exist at the time), an achievement often repeated by writer-director-producer James L. Brooks on his later films.
Although not specifically stated, the bulk of the story takes place over a span of several years during the late 1970s (a 1979 wall calendar is visible midway through the movie). Interestingly, as the character Garrett is an astronaut, this particular time period was exactly when his services would be least needed by NASA. The final Apollo mission was in 1975 and there would not be another manned spaceflight until the first Space Shuttle mission in 1981.
Shirley MacLaine and Debra Winger were both nominated for 1983's Best Actress Oscar, which went to MacLaine. On her way to the podium, she reportedly whispered to Winger, "Half of this belongs to you," to which Winger reportedly replied, "I'll take half."
The Auguste Renoir painting given to Aurora by her mother is referenced throughout the movie, first when Aurora tells Emma she considered (but decided against) giving it to her as a wedding gift, again when Emma calls Aurora asking to borrow money, and once more when Aurora uses it as an excuse to invite Garrett to her bedroom. The exact value of a Renoir original portrait is difficult to pinpoint for a specific point in time due to the infrequency of transactions. However, it's safe to say that had Aurora sold the painting through a reputable auction house around 1980, it would have sold for well over $100,000 and possibly close to $1 million.
James Garner turned down the role of Garrett Breedlove, and Sissy Spacek turned down the role of Emma. Year later they would co-star in the mini-series "Streets of Laredo" also written by Larry McMurtry.