虽然同样是地狱之王的儿子，和野心勃勃的哥哥卡修斯（汤米·里斯特 Tommy Lister 饰）与阿达利亚（瑞斯·伊凡斯 Rhys Ifans 饰）不同，尼基（亚当·桑德勒 Adam Sandler 饰）身材矮小个性又懦弱。在地狱夺取王位不成，卡修斯和阿达利亚决定转移战场来到人间，而他们的离去对于地狱来说却是致命的。 　　为了拯救父亲和整个地狱王国，尼基来到了人间，他的任务是将两个老奸巨猾的哥哥捉拿归案，对于老实的弟弟来说，这真的没问题吗？在人间，尼基结识了美丽温柔的女孩瓦拉莉（帕特丽夏·阿奎特 Patricia Arquette 饰），两人互生好感，可惜被阿达利亚设计破坏。对于尼基的追捕，阿达利亚当然不会坐以待毙，心狠手辣的他甚至试图将弟弟置于死地，不幸的是，他成功了。When somebody's mother is an angel and his father is the devil, life can be really confusing. For a sweet boy like Little Nicky, it just got a whole lot worse. His two evil brothers Adrian and Cassius have just escaped from Hell and are wreaking havoc on an unsuspecting earth. His dad is disintegrating and it's up to Nicky to save him and all of a humanity by midnight before one of his brothers becomes the new Satan.