Every week, host Rex Murphy presides over a lively discussion on an issue of national interest or importance and invites listeners to call in with their opinions and thoughts. The topics are usually related to Canadian politics. In addition to Murphy, the show has commentators who are experts or involved in the issue. They are interviewed by Murphy and answer questions from callers. The show has been running since 1965, when it was started to provide a nation-wide forum to discuss the then-proposed national health insurance system now in place in Canada.
On occasions in the past, the program has gone to air as Cross-Continent Checkup by involving a radio network in at least one other foreign country, such as National Public Radio in the United States, London Broadcasting Company (as it was then known) in Britain or the CBC's own Radio Canada International, and taking calls from English-speaking callers in all involved countries. In each case, callers generally call a toll-free number in their own country. Checkup, nevertheless, often receives calls from callers outside Canada.
The program was first broadcast May 16, 1965, during the bitter debate over whether there should be a national publicly-funded health-care system (hence the somewhat medical name of the show). It has proven to be a mainstay in CBC Radio's mandate to reflect Canada to all Canadians. Close to half-a-million listeners tune in every Sunday afternoon to hear a lively exchange of ideas between callers and invited guests, and a broad cross-section of opinion on the topic of the day. On average, 5,000 to 10,000 people attempt to call the program during the broadcast to join the discussion.