Yuvraj Vijay Singh (Salman Khan) is a rich businessmen and crown prince of Pritampur, who is soon to be crowned as king. He is engaged to Maithili (Sonam Kapoor) a princess from the royal family of a neighboring kingdom. However, due to his stiff and stubborn nature Vijay faces many problems with Maithili as well as with his brother and sisters. His rich half sisters Rajkumari Chandrika (Swara Bhaskar) and Rajkumari Radhika (Aashika Bhatia) live in a separate house outside the royal palace and h
ave filed case against Vijay for a share in the royal property, because they felt their mother (a poet and later mistress to the late King) was wronged by the Queen when she disgraced her in the presence of all of the King's children. Similarly, his half brother Yuvraj Ajay Singh (Neil Nitin Mukesh) vows vengeance and has been wanting to kill him and take the crown for himself. He enlists the help of his manager Chirag Singh (Armaan Kohli), who is misguiding Ajay at every step. Yuvraj Vijay barely escapes an assassination plan coordinated by Yuvraj Ajay and Chirag to kill him but gets badly injured. He's hidden in a secret chamber maintained by two doctors.
Meanwhile, Vijay's lookalike Prem Dilwale (Salman Khan), a perky, lively and carefree stage actor who falls in love with Princess Maithili, reaches Pritampur to meet her along with his friend Kanhaiya (Deepak Dobriyal). At a bus stop, the Security Head of Pritampur Palace, Sanjay (Deepraj Rana), notices him by chance, and takes him to Diwan Sahib (Anupam Kher). Upon witnessing the striking resemblance between Prem and Yuvraj Vijay, diwan asks Prem to take Yuvraj Vijay's place while Yuvraj recovers from coma. Prem acts as Yuvraj Vijay but with his simple and caring nature, he impresses Maithili who earlier wanted to break up with Vijay. Prem also attempts to reconcile with his sisters by bringing them back to the royal palace; he prepares legal documents handing over all of the royal family's properties to them. But his sisters are so moved by this gesture that, with a little push from Maithili, they eventually have a change of heart.
Meanwhile, Yuvraj Ajay and Chirag find out that Prem is only playing the part of the prince, and thus they kidnap the real Yuvraj Vijay. Chirag decides to double cross Ajay, as he frees Vijay and feeds him false information to pit him against Ajay and Prem. Vijay and Ajay get involved in a sword fight when Prem and Kanhaiya intervene and clear the confusion. Chirag tries to shoot them down but falls to his death. Ajay regrets his deeds, but Vijay reconciles with him. Maithili is shocked to know the truth about Prem not being Yuvraj Vijay, after Prem has left to return to his home. At the end, the royal family reaches Prem's house to reunite Prem and Maithili