The show scaled back to two hours in 1977 before WNEW canceled it in December of that year. The last produced show was taped December 21 before airing on December 25. In an interview on WNEW's local talk show "Midday with Bill Boggs" on the day of "Wonderama"'s cancellation, host Bob McAllister claimed to have no idea why the show ended. However, in a 1990s interview with the Southern California interview show "Remember When", McAllister stated that an advertisement that he bought in "The New York Times" telling viewers to stop watching "Wonderama" might have led to the program's cancellation. McAllister bought the "Times" ad after he became upset when an ad for the 1972 Charles Bronson movie "The Mechanic" aired during the show.