If reports are to be believed, Velayudham is yet another film against corruption. The story is about Vetrivel (Vijay), who resides in a village with his sister (Saranya Mohan). His love interest is Vaidehi (Hansika Motwani). When the time comes for his sister's marriage, he comes to Chennai to withdraw the money from a chit fund company, where he had deposited for a fixed period.
The story turns serious when he realized that it is a bogus company and he will not get back his money. At this juncture, he accidentally meets a journalist by named Deepa (Genelia D'Souza) during a bomb blast in the city in which goons get killed. But the people, who witnessed it, believe that Vetrivel killed them and start considering him as their hero.
Meanwhile, Deepa tells him to use this opportunity to fight against corruption and to get justice for the people, who have been cheated like him. The rest of the story is about what measures he takes to fight against the corruption and how he kills baddies.