Abbas Ali (Abhishek Bachchan) lives in Chandni Chowk with his sister Sania (Asin Thottumkal). When their ancestral property is taken from them by deception, Abbas loses his job. Their family friend, Shastri (Asrani), convinces them to move to his village, Ranakpur, where he assures Abbas that he will get him a job at his boss, Prithviraj Raghuvanshi's (Ajay Devgn), place. Pritvhiraj is a powerful but kind-hearted man who hates lies and liars, and punishes them harshly. Abbas and Sania arrive at Ranakpur and meet Abbas's friend Ravi (Krishna Abhishek), Shastri's son, who runs a drama company with his friends. Abbas learns that there is a temple at the border of Ranakpur and Kherwada, the village where Prithviraj's cousin Vikrant Raghuvanshi is powerful. The two cousins are archenemies. The temple, being at the border of the two villages, was disputed and has been locked for years.

The plot begins when a child falls into the well of the temple and Abbas breaks the temple's lock to save the child. When Prithviraj arrives at the scene, Ravi says Abbas's name as Abhishek Bachchan to avoid religious controversies of a temple being broken open by a Muslim. Prithviraj hires Abhishek Bachchan (Abbas) and is happy with his work, but Ravi and his friends have to come up with a new plan when Prithviraj spots Abbas celebrating Eid as a Muslim. Abbas and the others convince Prithviraj that the one celebrating Eid was actually 'Abbas', an effeminate man and classical Kathak dancer. Things become worse for Abbas and Ravi when Prithviraj kindly hires Abbas for teaching Kathak to his sister Radhika (Prachi Desai). The more Abbas tries to manage his dual life without letting Prithviraj know, the more he has to lie to cover up other lies; this forms the crux of the story. The movie ends with a climatic cliff scene where both Abbas and Pritihviraj make up after a series of lies.

• Ajay Devgn as Prithviraj Raghuvanshi
• Abhishek Bachchan as Abbas Ali / Abhishek Bachchan
• Asin as Sania Ali /Sania Bachchan /Apeksha (double role)
• Prachi Desai as Radhika Raghuvanshi
• Archana Puran Singh as Zohra / Madhumati
• Krishna Abhishek as Ravi
• Asrani as Shastri
• Amitabh Bachchan as himself in the title song "Bol Bachchan"
• Paresh Ganatra as Builder (cameo)
• Neeraj Vora as Maakhan
• Vijay Ishwarlal Pawar as Kailash (actor in Ravi's plays )
• Prasad Barve as Ravi's friend
• Jeetu Verma as Vikrant Raghuvanshi
• Robin Bhatt as Judge
• Krishna Shetty as Radhika Raghuvanshi's college friend.

Comparisons with Gol Maal

The plot and the characters of the film are based on the 1979 comedy film Gol Maal.

The film was originally expected for a Diwali 2011 release, though was postponed to 2012. On Dussehra 2011, director Rohit Shetty who previously directed the comedy flick, Golmaal 3 (2010), did first give actor Ajay Devgn an offer for Golmaal 4, but Devgn claimed "Golmaal 4 will happen next to next year. It's necessary to have two years gap between two Golmaal films. It's not good if it comes every year." After the announcement, it was added that Bol Bachchan will be made before Golmaal 4. In January 2011, it was revealed that actress Asin was roped in for the first female lead after Bipasha Basu rejected the role. Earlier, actress Genelia D'Souza was signed to play the second female lead, but due to her differences with the makers, she opted out of the project and hence the role was offered to Prachi Desai.

In Jubilee Comedy Circus, Krushna Abhishek did a performance of Rohit Shetty never giving him a film role to do but having promised him in earlier seasons of the show, Rohit was so impressed by the performance, he decided to give Krushna a role in Bol Bachchan. Shetty also added co-host Archana Puran Singh from the same show to the film cast. It was revealed in the 300th episode special of Comedy Circus, where Rohit Shetty was a guest judge, that Paresh Ganatra was among the cast. The film has been shot at various locations, including Rohit Shetty's seemingly favourite Panchgani and Chomu Palace, among other locations.

The music of the film was composed by Himesh Reshammiya while the lyrics were penned by Farhad-Sajid, Shabbir Ahmed, Swanand Kirkire and Sameer. The album was released on 7 June 2012 and included four original soundtracks along with four remix versions of the tracks. Three songs were composed by Reshammiya of which two were featured in the film and one was listed only in the album. One song, "Nach Le Nach Le", composed by Ajay-Atul was also included in the album. Among the songs, "Jab Se Dekhi Hai", "Nach Le Nach Le" became moderately popular.

All music composed by Himesh Reshammiya, except where noted.