为了获得更多的蓝精灵精华，邪恶巫师格格巫（汉克·阿扎利亚 Hank Azaria 饰）制造了两个调皮捣蛋的灰色小精灵韦克茜（克里斯蒂娜·里奇 Christina Ricci 配音）和海库斯（JB·斯穆夫 J.B. Smoove 配音）。可是他无法从灰精灵那里提取精华，为此格格巫派出韦克茜混入大森林，绑架了即将迎来生日的蓝妹妹（凯蒂·派瑞 Katy Perry 配音），希望能从她口中拷问出蓝爸爸（乔纳森·温特斯 Jonathan Winters 配音）将她变蓝的秘密。 　　为了营救蓝妹妹，蓝爸爸率领笨笨（安东·尤金 Anton Yelchin 配音）、厌厌（乔治·洛佩兹 George Lopez 配音）、浮浮（克里斯蒂娜·里奇 Christina Ricci 配音）重返人类世界，并在他们人类朋友的帮助下，展开了蓝妹妹的营救行动……The evil wizard Gargamel creates a couple of mischievous Smurf-like creatures called the Naughties that he hopes will let him harness the all-powerful, magical Smurf-essence. But when he discovers that only a real Smurf can give him what he wants, and only a secret spell that Smurfette knows can turn the Naughties into real Smurfs, Gargamel kidnaps Smurfette and brings her to Paris, where he has been winning the adoration of millions as the world¹s greatest sorcerer. It's up to Papa, Clumsy, Grouchy, and Vanity to return to our world, reunite with their human friends Patrick and Grace Winslow, and rescue her! Will Smurfette, who has always felt different from the other Smurfs, find a new connection with the Naughties Vexy and Hackus or will the Smurfs convince her that their love for her is True Blue?