Writer: Yunus Sajawal
Varun Dhawan as Raja / Prem Malhotra (Dual role)
Jacqueline Fernandez as Alishka Bakshi, Raja’s girlfriend
Taapsee Pannu as Samaara, Prem’s girlfriend
Anupam Kher as Balraj Bakshi, Alishka’s father
Sachin Khedekar as Mr. Rajeev Malhotra, Raja and Prem’s father
Prachi Shah as Mrs. Ankita Malhotra, Raja and Prem’s mother
Upasana Singh as Samaara’s Mother
Rajpal Yadav as Nandu
Manoj Pahwa as Sharafat Ali, Raja’s boss
Manoj Anand as Plane Passenger
Atul Sharma as Shopper
Donna Preston as Nancy
Hiten Patel as Alex’s Henchman
Pippa Hughes as Dancer
Pavan Malhotra as Officer Kuldeep Dhillon
Ali Asgar as Doctor Lulla, Prem’s therapist
Vivan Bhatena as Alex, Charles’ son and Raja’s enemy
Zakir Hussain as Charles, Malhotra’s enemy
Manoj Joshi as Alex’s Mama
Vikas Verma as Rocky
Johnny Lever as Pappu Passport
Rajat Rawail as Jewellery Showroom Owner
Vineet Sharma as officer
Aryan Prajapati as young Nandu
Naman Shri as Taxi driver
Salman Khan in a cameo appearance as Raja / Prem
While flying back to Mumbai, Rajeev Malhotra meets Charles, a criminal. Malhotra then rushes to the hospital where his wife has given birth to Twin sons. The doctor explains that when the twins are near each other, their reflexes operate simultaneously.
Malhotra has the authorities at the hospital waiting to arrest Charles. In the scuffle, Charles kidnaps one of the twins and leaves him at the train tracks. Charles is arrested and is sentenced to twenty years in prison. The police advises Malhotra to take his wife and Prem and leave India, so they move to London, England. The other twin is found by a woman named Kashibai and she raises him as her son in Mumbai, and names him Raja.
Twenty years later, Charles is almost about to be released from jail. Prem has grown up to be a kind and gentle Christian boy who aspires to be a musician. He is thrashed and bullied by an upperclassman, Rocky, on his first day of college and is pitied by Samaira. Samaira is impressed by Prem’s musical talents and asks him to come to her house and teach her music.
At the same time, Raja has grown up to be a fun-loving young man and staunch devotee of Ganpati Bappa, growing alongside his friend Nandu in the slums. One day, he gets in brawl with Alex, a local goon’s head, at the festivities for Ganesh Chaturti. Raja is warned to take Nandu and get out of India for a few days because Alex’s goons will go after them. Raja and Nandu illegally fly to London and meet Alishka on the flight. Raja starts dating Alishka and Prem begins dating Samaira.
Now that Raja and Prem are both in London and are in close proximity to each other, their reflexes start operating simultaneously, and this creates a lot of confusion for the both of them and their girlfriends. They are also mistaken for each other by many people in the city.
One day, after Raja and Nandu save Malhotra from an accident, they find Alex and his uncle and discover that Alex lost his memory after that incident. Raja and Prem finally meet each other. They don’t realize that they are twins and conclude that they only share the same face.
Alex regains his memory and bring Raja and Nandu to Charles, who is Alex’s dad. Charles holds Nandu hostage demanding Malhotra in exchange. Raja finally discovers that he and Prem are twins. Prem, disguised as Raja, brings Malhotra to Charles.
Raja arrives and beats up all of his goons. Alex’s uncle locks himself with Raja. But soon, Raja’s reflexes reciprocate helping Prem beat Alex. Raja and Prem find their father tied to a bomb and later deactivate it after Raja’s fluke.
The Malhotra family is finally reunited and Prem marries Samaira while Raja marries Alishka. They check out Raja and Prem outside who dance with them.