其貌不扬的退伍老兵巴尼·罗斯（西尔维斯特·史泰龙 Sylvester Stallone 饰）生活在城市的某个角落，事实上他却是一支特种兵的领袖，其麾下云集了李（杰森·斯坦森 Jason Statham 饰）、杨（李连杰 Jet Li 饰）等一众高手。正所谓艺高人胆大，只要酬金给足，再危险的任务也敢接。这天，来自中情局的教堂先生（布鲁斯·威利斯 Bruce Willis 饰）联系到巴尼，雇用他们前往位于南美的比莱纳岛，铲除与美国政府作对的独裁将军加尔萨（David Zayas 饰）。 　　由于任务艰险，巴尼和李先行探路，发现加尔萨与前中情局官员詹姆斯·门罗相互勾结，残酷压榨比莱纳岛的人民。不久巴尼和他的战友赶赴小岛，而更大的挑战正等待着这群骁勇的战士们……Barney Ross leads the "Expendables", a band of highly skilled mercenaries including knife enthusiast Lee Christmas, martial arts expert Yin Yang, heavy weapons specialist Hale Caesar, demolitionist Toll Road and loose-cannon sniper Gunner Jensen. When the group is commissioned by the mysterious Mr. Church to assassinate the merciless dictator of a small South American island, Barney and Lee head to the remote locale to scout out their opposition. Once there, they meet with local rebel Sandra and discover the true nature of the conflict engulfing the city. When they escape the island and Sandra stays behind, Ross must choose to either walk away and save his own life - or attempt a suicidal rescue mission that might just save his soul.