Although they have a long shared history, in recent years they have drifted apart, Dave pursuing an impressive legal career and Mitch pursuing as little as possible. They have become different people.
But on a night out on the town the two look at each other's lives and wish for a change in their circumstances. When they wake next morning, the change has happened and both men are forced to adapt quickly to their new lives.
The "new" Mitch has to perform in an adult movie while the "new" Dave must help close a major deal for his law firm.
It is here that the fun and games begin.
With a childlike innocence, the men are able to look at their lives through a different set of eyes and realise their shortcomings and also the many great things they have in their everyday lives.
There are some wonderful moments as Mitch discovers some of the realities of marriage and Dave tries his luck in the dating game.
Dave's wife, Jamie (Leslie Mann), and his sexy legal assistant, Sabrina (Olivia Wilde), do their best to work out what is going on with the guys and are key to many of the funniest moments in the movie.
If you don't mind the fact that The Change Up is not an original concept, there are plenty of laughs to be had as we watch the two men realise what is really important in their lives.
The Change Up (R16)
130 minutes
Stars: 3/5