Champak Chaturvedi (Paresh Rawal) the creator of a theatre group, is offered a chance perform a show in London. Bunty (Akshay Kumar) and Babla (Govinda) are two derps and flirts in his group, always fighting with each other to get the role of the hero. Their behaviour causes the actress (Tanushree Dutta) to run away. This really upsets the organizer, who offered the chance mainly because of the heroine. After reaching London, Champak tells the duo that whoever gets a new actress will get to become hero. Then Babla asks Gullu (Rajpal Yadav), a local driver where he can find a heroine. Gullu misinterprets this as prostitute and directs him to a park.
Bunty, who has heard everything, follows them. In a misunderstanding, they meet two men from underworld and exchange their goods, only to find that the men have sold drugs to them since the underworld misinterpreted their need for heroine as "heroin". Bunty convinces Babla into going to the police to turn in the drugs to get good credit or an award, but the police get the wrong impression and think they are drug dealers. Commissioner JD Mehra (Jackie Shroff) releases them after telling them not to leave the country until they are proven innocent. Then while search of a heroine, Bunty and Gullu take help of Guru (Shakti Kapoor), a local don who is a drunkard and they end up breaking his (Guru's) legs. Guru sends his goons to thrash Bunty and Gullu but they escape. They bump into Munni (Lara Dutta), who is trying to commit suicide. Bunty saves her and brings her to the theatre group to be the heroine.
Later, Bunty falls in love with Munni, but then she has an accident. The doctor notes that she may have suicidal tendencies. When Munni wakes up, she claims to be Nisha Chauhan, wife of Vikram Chauhan (Arbaaz Khan). They meet Vikram, who confirms her suicidal nature. A heartbroken Bunty accepts the fact and tries to forget her, only to learn some time later that Nisha has burnt herself to death.
Meanwhile, the underworld don (Sharat Saxena) who gave drugs and his boss M.G. Gandhi (Manoj Joshi) think that Bunty, Babla and Champak are undercover cops and they want to kill them. However, Bunty suddenly spots Nisha in the city one day. Later, Champak and Babla too see her. On the day of the drama, the trio see Vikram flailing a gun at someone and are shocked to see him die in front of them.
All three are frightened and throw his body down a vent. During the performance, Vikram's body falls from the ceiling. The commissioner questions everyone and arrests the trio for murder of Vikram. M.G. Gandhi wants the three dead because he thinks they're going to get him thrown in jail. Gandhi's men attack the police car transporting the trio, helping them to escape. The trio try to search priety based on the clues they have. Meanwhile Gullu is given task by Guru to search for the trio. M G Gandhi captures Champak. Bunty and Babla run into Nisha, well and alive, upon which they trap her at the clock tower of Brighton railway station.
It is revealed her real name is Aditi and she was hired by Vikram to play his wife Nisha and convince people she is crazy in return for money and a passport out of the UK. Vikram wanted to kill his real wife Nisha to get her wealth. When Aditi found out about his ways, she tried to stop him and failed. She later tried to reach Bunty at the show to tell him about it, but Vikram caught her. Then the Commissioner arrived at the play and killed Vikram. Just then, the Commissioner arrives there and confirms that he is indeed Vikram's killer.
The Commissioner reveals that Nisha was his sister and he killed Vikram to avenge her murder. He also intends to kill Aditi as she helped Vikram to pass off Nisha's murder as suicide. By then, Gandhi and his men, Champak, Gullu, Guru and his men, reach there and a skirmish starts. The Commissioner is about to kill Nisha along with Bunty, Babla and Champak. However, the disaster is averted, after which the Commissioner confesses his crime. Bunty marries Aditi. The film ends with the title song.