迈阿密警局的一对“黄金”搭档，顾家爱妻的好男人宾纳（马丁•劳伦斯）和衣着光鲜风流倜傥的富家子弟劳瑞（威尔•史密斯），奉命追查一桩价值上亿美元的毒品证物失窃案，如果不能及时完成任务，他俩就得卷铺盖走人。 　　在两人疲于奔命之际，该案件唯一的性感女证人打电话到警局声称她愿意指认主谋，但条件是劳瑞必须出面保护她，否则一切免谈，此时劳瑞刚好不在警局，宾纳为套取线索，急中生智冒名顶替。其后，为了不失去女证人的信任，两人只得将对调身份一事进行到底，宾纳在枪林弹雨及汽车追逐中贴身保护女证人，劳瑞则来到他家中陪伴其妻。Marcus Burnett is a hen-pecked family man. Mike Lowry is a foot-loose and fancy free ladies' man. Both are Miami policemen, and both have 72 hours to reclaim a consignment of drugs stolen from under their station's nose. To complicate matters, in order to get the assistance of the sole witness to a murder, they have to pretend to be each other.