Cash is a fast-paced adventure thriller movie. The movie revolves around a villain (Sunil Shetty), three conmen-turned-enemies (Ajay, Riteish, Zayed), Shamita Shetty (the head of a security firm chasing the conmen) and Esha (Riteish and Zayed's love interest).Cash has been completely shot in the picturesque city of Cape Town. The tourism department of South Africa also hopes that “Cash” will increase the tourist flow to Cape Town.
The story rotates around three unique diamonds that are needed by many. Shamita Shetty plays the role of Divya Gupta, head of security at the Indian embassy in Cape town. Divya is responsible for the security of the three diamonds. While Divya has been given the responsibility to ensure the safe transportation of the diamonds, she is completely unaware that her boy friend, Ajay Devgan is a con man who has been given the order from a top villain called Mint to rob the convoy containing the third diamond. The diamond is highly valued because it completes a set of three diamonds, two of which is already available. Ajay is also unaware that his girlfriend is a top security person.
The responsibility to steal the diamond is something Ajay can’t do alone. He has to take the help of three experienced top con people from Mumbai. These three are Esha, Riteish, and Zayed. The only problem Ajay has is that the three can’t stand each other and will not work with each other. The reason being a girl, Sania played by Esha Deol. Initially the three of them made a great team pulling away lot of con acts together. However, both the guys fall in love with Sania and Sania falls in love with one of them. Sania is unable to face the other one and tell him that. So both Sania and her lover decide to break up and never see each other again. Their third buddy, is unaware of the cause of the split but knows his friend is responsible for it. Hence, the hatred for him. Ajay is aware that only these three can help him pull the robbery off. He sets about making a plan which would unravel such that each is unaware that the other is also working in the same mission. The plan is something like a chain reaction in which each character plays a role.
The entire con team carries off the robbery. After the success of the robbery, Ajay realizes that he has landed his girl friend into problem. He also has landed into trouble as the money he has stolen as part of the mission is marked by the embassy. Without realizing Ajay and his team have been started spending the marked money. Ajay hands over the diamond to Mint who double crosses his boss. Mint kills his boss when he realizes that his boss has the other two diamonds of the set.
Now starts another Herculean task. Robbing the diamond back from Mint and replacing it in the embassy before the police and Ajay’s girlfriends realize their identities. In between all this the three friends get to know that they were working on the same mission. They realize that they are still good friends and that Sania actually loved her third buddy and the not the one with whom she split. Sania is kidnapped by Mint. Rest of the movie is anybody’s guess.