Harinder Singh Nehra, also known as Harry (Shah Rukh Khan), is a middle-aged tourist guide in Europe. He is good at his work but is not settled in life. He has flings and affairs with available girls and then moves on and thus he is a womanizer in his own sweet little way. Sejal (Anushka Sharma) has come from India on a trip to Europe, with family and other acquaintances. Rupen (Kavi Shastri), who is in the same group as Sejal, gets engaged to her during the foreign trip. Harry is the guide for Sejal’s group.

As bad luck would have it, Sejal loses the engagement ring which infuriates her fiancé because the ring which belonged to his grandmother, holds sentimental value for him. Rather than return to India, Sejal stays back alone to get hold of her ring as she believes, it would be easy to trace it. She catches hold of the tourist guide, Harry, who very reluctantly agrees to help her.

Since the ring cannot be found, Harry and Sejal move from one city to another, covering all the destinations which Sejal and her group had visited. In the process, Harry and Sejal fall in love with one another. He tells her that he had left his home in Nur Mahal village and came to Canada to become a singer, which did not work out.

Harry holds himself back because he feels, this relationship would lead to nowhere as Sejal is already engaged. Besides, Harry considers himself a loser, having lost in love in the past. He also thinks his views on sex and life would never go down well with Sejal. In fact, he keeps asking Sejal to not get serious with him because of the aforementioned reasons. On her part, Sejal is keen to erase Harry’s past from his memory and towards this, she even asks him to return to his hometown in India at least once, something which Harry can’t get himself to do because of memories of his past.

They soon learn that a criminal, Gas, has stolen the ring. They go to Gas to retrieve the ring but Harry gets thrashed by Gas's men. Later, while looking for antiseptics in her bag for Harry, Sejal finds the ring and realizes that the ring was in her bag all along. However, she does not tell Harry about this.The next day, Harry and Sejal fly to Frankfurt for the wedding of Mayank; Harry's friend. After the wedding, Harry and Sejal get into an argument and she decides to leave for India.

At the airport, Sejal shows Harry the ring and tells him that it was in her bag all along. He asks her to take care and bids her goodbye. She returns to India and he returns to his work but begins to miss her and gets depressed. On Mayank's insistence, Harry flies for Mumbai to go to her wedding. On reaching the venue, he learned that her marriage was called off and finds her sitting outside. They eventually share their feelings for each other and go to Harry's village, Nur Mahal, where he reunites with his family and marries Sejal.