In several outdoor scenes, snow is simulated with foam.
A sequel titled "Still Running" was planned and different scripts were written. But Billy Crystal and Gregory Hines did not think any of them were strong to warrant a sequel and turned them all down.
After returning from Florida, Ray wears a Tampa Bay Buccaneers hat. At the time the movie was filmed, the Buccaneers and Chicago Bears were division rivals.
On the television series, "The Directors", Peter Hyams stated that when MGM offered him the project following the success of 2010: The Year We Make Contact, the script focused on two old New York City cops who want to retire. Hyams suggested his idea of two young Chicago cops who don't retire and MGM agreed.
A plot device is borrowed from The Black Windmill (1974). In one film Michael Caine's son is kidnapped and to get the ransom (uncut diamonds) he impersonates his boss (Donald Pleasence) on the phone and gives himself permission to take the diamonds from work (MI5). In the other Billy Crystal's ex-wife is kidnapped and he impersonates his boss ('Dan Hedeya') on the telephone to give himself permission to take the ransom (cocaine held as evidence) from work (Chicago police department).
The original script was written for Gene Hackman and Paul Newman before Peter Hyams decided to make the Hughes and Costanzo characters younger.