李督察（成龙 饰）和从洛杉矶赶来香港度假的老搭档詹姆斯•卡特（克里斯•塔克 Chris Tucker 饰）真是一刻不得闲，因美国领事馆遭到炸弹袭击，两名工作人员身亡，李督察只得带上卡特去拜访三合会头目、也是自己父亲的昔日搭档邓力奇（尊龙 饰），邓力奇的手下胡莉（章子怡 饰）等人先后出面袭击李与卡特，不久李被美国方面禁止参与此案，而香港警局也遭到了炸弹袭击。失散的李和卡特分别来到了邓力奇的游艇，得知三合会出现了内讧，话音刚落，胡莉将邓力奇射杀在海中……暂时失去线索的二人奔赴洛杉矶，在当地大亨荣士勋家中发现了胡莉的踪迹和美国的卧底特工，原来邓、胡等人卷入了一场巨额假钞案，李与卡特决定拿回胡莉手中的印版……It's vacation time for Det. James Carter and he finds himself alongside Det. Lee in Hong Kong wishing for more excitement. While Carter wants to party and meet the ladies, Lee is out to track down a Triad gang lord who may be responsible for killing two men at the American Embassy. Things get complicated as the pair stumble onto a counterfeiting plot by L.A. crime boss Steven Reign and Triad Ricky Tan, an ex-cop who played a mysterious part in the death of Det. Lee's father. Throw in a power struggle between Tan and the gorgeous but dangerous Hu Li and the boys are soon up to their necks in fist fights and life-threatening situations. A trip back to the U.S. may provide the answers about the bombing, the counterfeiting, and the true allegiance of sexy customs agent Isabella. Then again, it may turn up more excitement than Carter was looking for during his vacation.