Fred works as a department store Santa to pick up some extra holiday cash. He is so successful that the real Santa Claus, who is ill, asks him to take over delivering toys on Christmas Eve. Fred does, but in his rush he forgets to deliver presents to his own house. To his delight, he finds Santa has already taken care of it.

In this feature-length film based on the "Flintstones" TV show, secret agent Rock Slag is injured during a chase in Bedrock. Slag's chief decides to replace the injured Slag with Fred Flintstone, who just happens to look like him. The trip takes Fred to Paris and Rome, which is good for Wilma, Barney, and Betty, but can Fred foil the mysterious Green Goose's evil plan for a destructive missile without letting his wife and friends in on his secret?

Fred Flintstone and Barney Rubble quit their jobs at the gravel pit, drink Busch Beer for inspiration, watch a preview for Busch's advertising in 1967, and take up new positions as bartenders.