Nicky (Adam Sandler) is just a guy who'd rather play heavy metal music in his bedroom sanctuary than climb the corporate ladder in his family's thriving business. Ruthless older brothers Adrian (Rhys Ifans), and Cassius (Tiny Lister) are much more ambitious.

When their aging father (Harvey Keitel) decides to postpone his retirement, the sinister duo defects, leaving home, to set up shop in a new location: New York City. This is about to become a big problem for the "Big Apple." Nicky's dad is the Devil himself. Adrian and Cassius evade the Gatekeeper's (Kevin Nealon) efforts to stop them and make a hasty exit from Hades. As a result, the gates of hell freeze over and with no more evil souls able to enter, their dad starts to fall apart-- literally!

It's up to Little Nicky to save him by finding his rotten brothers and bringing them home before his dad wastes away. The problem is, Nicky has never been to earth. In fact, he has never left his house...