Three lively singing chipmunk brothers, Alvin - the unchained leader, Simon - the genius, and the tender rotund Theodore are living their lives in the forest storing nuts away for the winter when one day their tree is cut down and carried off into the city to become a Christmas tree. They must find a new home and they end up at Daves house.
The only thing that makes them different is that they can talk and even sing. Dave Seville (Jason Lee) is a struggling song writer who has a great idea about making the chipmunks a new show act, singing his songs. The only thing is that you must remember is that they are chipmunks and they act like chipmunks by tearing up Daves house and interrupting his love life.
David will adopt the Chipmunks taking care of them as lovely father and manager of their famous rock band. The chipmunks become a big hit and superstars with cute voices and fancy dance moves. The record company executive Ian (David Cross) sees big money in his future and takes over the act and pushes Dave to the side. Dave must try to save his little family before they becomes a show biz disaster.