Leslie Nielsen, who played the recurring role of Canadian Mountie Buck Frobisher, was the real-life son of a Mountie.
For a while, this was the most popular Canadian-based and produced television series ever shown on a U.S. network. After a break in production following the first two seasons, the producers found international funding to continue production.
In its third season, when the show moved from CBS to first-run syndication, the new production company wanted the premise inserted into the opening titles, so first-time viewers wouldn't wonder what a Canadian Mountie was doing in Chicago. Paul Gross opted to include the premise in each episode, with "I first came to Chicago on the trail of the killers of my father, and for reasons that don't need exploring at this juncture, I've remained, attached as liaison with the Canadian Consulate." It became a running gag throughout the third season, as the writers found different ways to insert the line into almost each script, whether it was spoken by Fraser or other characters.
David Marciano opted not to return to the series after a contract dispute with Alliance Atlantis, the production company. His character, Ray, was replaced by Callum Keith Rennie. The writers wrote Rennie into the story by saying the original Ray Vecchio had gone deep undercover with the mob.
Leslie Nielsen's recurring character, legendary mountie Buck Frobisher, was named for sixteenth century explorer Sir Martin Frobisher, who explored what is now the Canadian Arctic searching for the Northwest Passage. Iqaluit, capital of Nunavut, was called Frobisher Bay until 1999.