A young couple sneak into a house, The Nath Villa, a huge bungalow in Goa. They meet with some supernatural events, only to discover a ghost lives in this house, and they run from there. Days later, Aditya and Anjali shift along with their kid Banku in the house. Aditya is an engineer working on a cruise line and leaves for it while Anjali hires Anthony, a drunk thief as a cleaner. One night, Banku sneaks down the dining room to enjoy the ice cream and encounters a ghost named Kailash Nath. Banku nicknames him Bhoothnath, amix of bhoot (ghost in Hindi) and Nath, being his surname.

Though Bhoothnath tries to scare him off, Banku considers him an angel and treats him like a friend. Soon, Bhoothnath accepts by Banku's innocent love after a minor incident, as Banku falls from the stairs which Bhoothnath claims responsibility for. The two become friends and thoroughly enjoy the company of one another. Days later, Bhoothnath's son, Vijay Nath, returns from the US and plans to sell off the bungalow. Angered, Bhoothnath scares the buyers, but Anjali comes to know about the existence of him. He then tells his story to Banku and Anjali through flashbacks.

Many years back, Kailash Nath has a happy family consisting of him, wife Nirmala along with son Vijay and his own family. Vijay tries to sell the house, but Bhoothnath disallows him though Vijay's wife is in hurry to fly US. He tries to stop him but fails. On the day of departure, Vijay's son is taken away despite his will. Bhoothnath tries to stop them, but his foot slips on a step and he falls to the ground. Bhoothnath, unaware that he has just died, rises and reaches for the taxi but is late as it has already departed. As he sighs and walks inside, he collapses in shock after seeing his dead body lying by realising he is now a ghost.

Later, Aditya and Anjali decide to perform the final rites of Bhoothnath to give him salvation. As Banku and his father perform the rites, Vijay arrives and apologizes for his mistake. Vijay, along with his wife and son, reside in Nath Villa with Banku and his parents permanently. A distraught Banku arrives at his school, and as he parks his cycle, he is happily reunited with Bhoothnath who has returned but requests Banku and the viewers to hide the secret.

• Amitabh Bachchan as Kailash Nath (Bhoothnath)
• Shah Rukh Khan as Aditya Sharma
• Juhi Chawla as Anjali Sharma
• Aman Siddiqui as Aman "Banku" Sharma
• Satish Shah as Principal J.J. Irani
• Rajpal Yadav as Anthony
• Priyanshu Chatterjee as Vijay Nath
• Shaana Diya as Shaana (Vijay's wife)
• Neena Kulkarni as Nirmala Nath
• Delnaaz Paul as Jojo's mother
• Aashish Chaudhary as Rohan (Special Appearance)
• Nauheed Cyrusi as Tina (Special Appearance)
• Amit Behl as Doctor
• Achyut Potdar as Temple Priest

All songs composed by Vishal-Shekhar with lyrics by Javed Akhtar.

The film received generally positive response from critics. IMDb rated it 6.9/10, and it's Rotten Tomatoes rating is 76%. At the box office, the film had a good opening, though managed to gross ?68 million (US$1.0 million) among its theatrical run and was declared semi-hit by Box Office India.

As the movie finished with a "to be continued..." ending, a sequel to Bhoothnath was expected but there was no clear intention. Amitabh Bachchan and the original production team announced a sequel, titled Bhoothnath Returns, released on 11 April 2014. Bachchan and Shahrukh Khan reprised their roles, though latter Shahrukh Khan only had a cameo appearance

• List of ghost films
• The Canterville Ghost