Fred Flintstone (JOHN GOODMAN) is a devoted husband to Wilma (ELIZABETH PERKINS) and father to Pebbles (ELAINE SILVER AND MELANIE SILVER), and a fine friend to Barney Rubble (RICK MORANIS), having recently given a sizable amount of money to him and Betty (ROSIE O'DONNELL) so they can adopt a kid. But he wants to be someone, more than he is now.
He gets his chance when Cliff Vandercave (KYLE MACLACHLAN), a vice president at Slate Rock & Gravel Company, announces a test to determine who will be the next executive at the company. Barney, grateful for what Fred has done for him and Betty, switches his and Fred's test after the exam is over, and Fred becomes the new executive, living the rich life, and finally being someone.
But Cliff's scheme, with his associate Miss Stone (HALLE BERRY), is to embezzle money from the company, but make it look like someone else did the deed. That's the position Fred's in, but he doesn't know it right away. And the Flintstones' friendship with the Rubbles is also strained by their newfound riches.