乔（大卫·斯佩德 David Spade 饰）是一个众所周知的傻孩子，每天都调皮捣蛋招惹一堆的麻烦，终于有一天，乔的父母忍无可忍，于是决定将乔抛弃在一个陌生的城市之中。遭到抛弃的乔无依无靠，只能够凭借着本能在冰冷的城市中孤独的生存下去，好在他傻人有傻福，不仅顺利的长大了，还给自己找到了一份正儿八经的工作。 填饱了肚子的乔开始思念起自己的父母了，于是，他决定驱车去寻找他们。可是，这么多年的杳无音信，想要寻亲哪是这么容易的事情。一路上，乔遇到了不少的麻烦，却也结实了很多善良的朋友，漂亮姑娘布兰迪（布兰特妮·丹尼尔 Brittany Daniel 饰）更是“独具慧眼”，对乔青睐有加。Joe Dirt is a janitor with a mullet hairdo, acid-washed jeans and a dream to find the parents that he lost at the Grand Canyon when he was a belligerent, trailer park-raised eight-year-old. Now, blasting Van Halen in his jacked-up economy car, the irrepressibly optimistic Joe hits the road alone in search of his folks. As his wandering, misguided search takes him from one hilarious misadventure to another, Joe finds his way to Los Angeles, where a shock-jock brings Joe on his radio show to insult him. But as Joe's life story unfolds, jeers turn to cheers, and an entire captivated city tunes in to hear the adventures of Joe Dirt.
