Written by Jaideep Sahni, the film stars Anupam Kher, Boman Irani, Parvin Dabas, Vinay Pathak, Ranvir Shorey and Tara Sharma in the lead roles.

The story follows Kamal Kishore Khosla (Kher), a middle-class Delhiite and his family's attempt to reclaim their land which has been seized by a builder, Khurana (Irani).

However, Cherry, a software engineer, is not too enthusiastic about his father's plans and intends to move to New York, America to take up a job there, although he has not revealed this to his family yet.

The only people Cherry discusses this matter with is his girlfriend, Meghna (Tara Sharma), a small-time actress, and Asif Iqbal (Vinay Pathak), the travel agent helping him with his passport and visa paperwork.

On further enquiry with Vijendar, they realise that the squatters are part of a property usurping nexus headed by an unscrupulous and powerful local builder, Kishan Khurana (Boman Irani).

It eventually turns out that Vijendar was Khurana's accomplice in the plan and advises Kamal and Bunty to bid for the plot in order to reclaim it.

Kamal, Bunty, Cherry, and Sahni appeal to local government authorities and political agencies (police, lawyers, ministers, and social workers) for assistance regarding this matter.

Moved by his father's helplessness, Bunty decides to take action and seeks help from a gang of local wrestlers, who demolish the boundary walls constructed by Khurana's henchmen and successfully reclaim the possession of the plot by force.

Cherry, Asif, Meghna, and Bunty orchestrate a scheme for Khurana involving another plot of land owned by the "Fisheries Department", which is of 9 acres and is right next to the highway, but has been vacant for decades.

As part of their plan, Cherry, Asif, Meghna, and Bunty provide Bapu and Mani 2 mobile phones with numbers of Dubai, a rented Mercedes car with a driver, and a room in a 5-star hotel.

In the meeting, Bapu uses Khurana's love for Mata Vaishnodevi to create a personal bond with him while refusing to acknowledge Munjal and Vijendar.

The rest of the actors in Bapu's theatre group help create a convincing scenario for Khurana and Munjal, prompting them to believe the authenticity of the land and its owner, Sethi Associates.

Before the payment, Khurana and Munjal request to visit the land again, forcing the Khoslas, Meghna, and Asif themselves to secretly take on the roles of the labourers there, as the actors in Bapu's theatre group have now gone to Bangalore to perform at film festivals.

At the Khoslas' home, everyone is tremendously worried about Khurana cleverly coercing Bapu into confessing the truth about Sethi Associates being an illegitimate party.

However, Bapu and Mani successfully deceive Khurana, taking the ₹35 lakhs in cash from his farmhouse to the Khoslas' home, which they hand over to Cherry, Asif and others, leaving them all ecstatic.

Cherry decides to change his name to Chirag and abandons his plans to move to the New York, while Bunty starts his own real estate business.

The film ends with a scene of Khurana learning from Munjal that he has been deceived and deciding to cover up the sham deal with Sethi Associates in order to protect his own reputation.

[3] The initial idea of the generation gap was conceived by Savita Raj Hiremath and her writer friend Jaideep Sahni, who had worked with Banerjee on advertising films.

[4] Banerjee said a real life experience when Sahni witnessed his father being insulted by someone powerful, helped them to develop the character of the antagonist Khurana.

"[3] Irani had also initially refused the offer to play Khurana as he felt he was unsuitable for the role of a builder from Delhi since he was a Mumbai-born Parsi.

[11] It consists of five songs with vocals by Kailash Kher, Kunal Ganjawala, Sowmya Raoh, Adnan Sami and Qadar Niazi Qawwal.

Savita, the film's producer, managed to raise some funds for the music and Sahni wrote the lyrics the same day as he was worried they might miss the opportunity.

Banerjee called him after hearing his music samples and asked him to create "a Punjabi number based on the loud attitude of Delhi."

Rajeev Masand lauded the film for its "refreshingly original plot, bang-on casting, killer soundtrack and such crisp editing that there is never a dull moment".

"[21] Namrata Joshi described the film as "utterly discreet and unassuming", one that "tries to bring back the clean and simple story-telling of Sai Paranjpye and Hrishikesh Mukherjee.

"[23] Sudhish Kamath of The Hindu included the film on his list of top 10 movies of the decade 2000–2009 saying: "Dibakar Banerjee and Sahni on a shoestring budget chose to bat for the common man's struggle against the powerful and reunited the individual self back with the family.

"[24] David Parkinson of Radio Times wrote: "Switching between bright comedy and social drama, this is Bollywood entertainment with a conscience.

"[25] In September 2018, Bhaskar Chawla of Arre noted that the film had "set the template for what was to become a new direction in Hindi cinema" that went "beyond the conventional formula of Bollywood.

[28] In October 2015, Banerjee decided to return the award to the government along with 12 other filmmakers, to protest the Ministry of Information and Broadcasting's refusal to roll back Film and Television Institute of India's appointment of Gajendra Chauhan as its chairman.

[31][32][33] It was included in Filmfare's 100 Days series—"With no big stars, relatively unheard of a director and a subject that you wouldn't rate on paper as the most exciting, Khosla Ka Ghosla manages to impress one and all.