The film opens with a depiction of the strong leadership of trade unionist Anand Verma (Satyen Kappu), who works hard to enhance the lives of struggling labourers. He lives in a modest home with his wife, Sumitra Devi (Nirupa Roy), and their two young sons, Vijay (Amitabh Bachchan), and Ravi (Shashi Kapoor). Anand, however, is blackmailed by a corrupt businessman who threatens to kill his family if Anand does not cease his protest activities. Forced into compliance, Anand is thus attacked by the very same labourers who then jeer him for his betrayal, unaware that he was blackmailed. His family is also persecuted by the angry workers. Out of shame, Anand leaves town, leaving Sumitra to care for their sons alone in poverty. Several of the angry workers kidnap Vijay and tattoo his arm with the Hindi words "???? ??? ??? ??" (mer? b?p chor hai) (meaning "my father is a thief"). Not knowing what else to do, Sumitra brings her children to Bombay and struggles as a day labourer to care for her now homeless sons.

Vijay, the older brother, grows up with an acute awareness of his father's failure and is victimised for his father's supposed misdeeds. In the process of fighting for his rights, Vijay, who starts out as a boot polisher, was a dockyard worker in his youth, now becomes a smuggler for the underworld. Vijay beats up several thugs working for their ruthless leader Samant (Madan Puri), which then influences one of Samant's rivals to bring Vijay to his inner circle, leaving Vijay to become a new leading figure of the underworld. He also sacrifices his own education so his brother Ravi can study.

Ravi is an excellent student. He is dating Veera (Neetu Singh), the daughter of a senior police officer. On the Commissioner's suggestion, Ravi applies for employment with the police, and is sent for training. Several months later, he is accepted by the police, and has a rank of Sub-Inspector. When Ravi returns home, he finds that Vijay has become a businessman overnight, has accumulated wealth, and a palatial home. One of his first assignments is to apprehend and arrest some of Bombay's hardcore criminals and smugglers which includes his brother, Vijay – much to his shock, as he had never associated his own brother with criminal activities. Ravi must now decide between apprehending Vijay and quitting the police force. When Ravi finds out that Vijay has acquired wealth by crime, he decides to move out along with his mother. Shouldering past the loss of his mother and sibling, Vijay enters a sexual relationship with Anita (Parveen Babi), a woman whom he meets at a bar. When Anita falls pregnant, Vijay decides to abandon his life in the underworld, marry her, and confess his sins. He also hopes to seek forgiveness from his mother and brother. However, when Anita is brutally murdered by Samant, Vijay loses all sense and brutally murders Samant in revenge for Anita's death, leading him to be branded a criminal forever. Their mother, who had sided with Ravi despite the fact that Vijay was her favourite, is tormented by Vijay's decisions and rejects him. When the two brothers meet for a final clash, Ravi, pleading Vijay to stop running, shoots Vijay in his arm and Vijay dies (after crashing his car into a wall while trying to escape) in his mother's arms in a temple, seeking forgiveness. Ravi is felicitated for pursuing justice.

• Shashi Kapoor as Ravi Verma, the younger brother
• Amitabh Bachchan as Vijay Verma, the elder brother
• Nirupa Roy as Sumitra Devi, mother of Vijay and Ravi
• Parveen Babi as Anita, Vijay's girlfriend
• Neetu Singh as Veera Narang, Ravi's girlfriend
• Satyendra Kapoor as Anand Verma, father of Vijay and Ravi
• Manmohan Krishna as DCP Narang, Veera's father
• Madan Puri as Samant
• Iftekhar as Mulk Raj Daavar
• Sudhir as Jaichand
• Jagdish Raj as Jaggi
• Raj Kishore as Darpan
• Yunus Parvez as Rahim Chacha, Head Porter
• Mohan Sherry as Peter's henchman
• Alankar Joshi as Young Vijay Verma
• Raju Shrestha as Young Ravi Verma
• Rajan Verma as Lachhu
• A. K. Hangal as Chander's Father
• Dulari as Chander's mother
• D. K. Sapru as Mr. Agarwal
• Kamal Kapoor as Anand Verma's employer

• Director: Yash Chopra
• Story: Salim-Javed
• Screenplay: Salim-Javed
• Dialogue: Salim-Javed
• Producer: Gulshan Rai
• Cinematographer: Kay Gee
• Editor: T. R. Mangeshkar, Pran Mehra
• Art Director: Desh Mukherjee
• Stunts: M. B. Shetty, Kodi S. Irani
• Music Director: Rahul Dev Burman
• Lyricist: Sahir Ludhianvi
• Playback Singers: Asha Bhosle, Manna Dey, Kishore Kumar, Bhupendra Singh, Ursula Vaz, Usha Mangeshkar

Story and screenplay

The film's screenplay, story and dialogues were written by Salim-Javed (Salim Khan and Javed Akhtar). The main inspiration for the film's plot was the 1961 Dilip Kumar film Gunga Jumna (1961), which had a similar premise of two brothers on opposing sides of the law, with the elder criminal brother as the main character. Deewaar is thus considered to be a spiritual successor to Gunga Jumna. Salim-Javed credited Gunga Jumna as well as Mehboob Khan's Mother India (1957) as the main inspirations for Deewaar, which they described as a "more urban, much more contemporary" take on their themes; while Mother India and Gunga Jumna took place in a rural context, Salim-Javed reinterpreted their themes in a contemporary urban context with Deewaar.

Amitabh Bachchan's character, Vijay, was loosely inspired by the real-life Bombay underworld gangster Haji Mastan. Vijay's story arc in the film parallels that of Mastan's life, such as the rise from a humble dockyard coolie worker to a powerful smuggler, and Mastan's rivalry with smuggler Sukkur Narayan Bakhia is similar to Vijay's rivalry with Samant (Madan Puri).

Salim-Javed's screenplay had dynamic dialogues, and incorporated a number of symbolic motifs. For example, the scene where the two brothers meet as adults takes place under a bridge, symbolising a bridge between the two "deewaars" ("walls") represented by the brothers. Set in the Dharavi slums of Bombay, the film's story of gangsters in Dharavi was a critique of socio-political inequality and injustice in Bombay. The characterisations of the two brothers are sociologically contextualised to represent a form of urban conflict and drama, aimed at presenting a causal explanation for the sequence of events and Vijay's social alienation, with the narrative explaining his every action and decision, grounded in his memories and experiences.

The script generally has an atmosphere of secularism, while incorporating subtle religious motifs. The mother Sumitra Devi (Nirupa Roy) and police brother Ravi (Shashi Kapoor) are religious Hindus, whereas the criminal brother Vijay (Bachchan) is generally not religious and "upset with God", yet he carries a badge numbered 786, which the Muslim Rahim Chacha (Yunus Parvez) points out to be a number of religious significance in Islam (representing Bismillah) and has its own sub-plot. The 786 badge plays a powerful and symbolic role in several scenes, saving Vijay at key moments and signifying something ominous when he loses it.

Salim-Javed initially showed the script to Bachchan, who they had in mind for Vijay's role after having worked with him on Zanjeer (1973). At the time Bachchan was working on another film with Yash Chopra, and told him about the script. After some initial scepticism, Chopra was eventually convinced to direct the film after Salim-Javed narrated the storyline to him.

Casting and filming

Bachchan's "angry young man" performance as Vijay in the film was inspired by Dilip Kumar's intense performance as Gunga in Gunga Jumna, which Bachchan sharpened and reinterpreted in a contemporary urban context reflecting the changing socio-political climate of 1970s India.^[24][25]

Producer Gulshan Rai initially wanted Rajesh Khanna to play Vijay's role. However, Salim-Javed "felt only he (Bachchan) could do justice to Vijay’s role." According to Akhtar, they "saw his talent, which most makers didn’t. He was exceptional, a genius actor who was in films that weren’t good." At Salim-Javed's insistence, Bachchan was cast in the role.^[8] Director Yash Chopra's first choices for Vijay and Ravi's roles were Rajesh Khanna and Navin Nischol, respectively, but Salim-Javed had Amitabh Bachchan and Shatrughan Sinha in mind when they wrote the script; Sinha turned down the film when he heard Khanna was initially cast in the lead, due to a fallout between the two. Nirupa Roy's role as Sumitra Devi was also first offered to Vyjayanthimala; Nischol and Vyjayanthimala turned down the film after they found out Khanna would no longer be in the film. Shashi Kapoor was subsequently cast as Ravi, and Nirupa Roy as Sumitra Devi.^[26]

In 2014, Bachchan revealed that his iconic look in the film – a "denim blue shirt worn with khakee pants and a rope dangling over the shoulder" – was the result of a mistake by the tailor. He said, "The knotted shirt and rope on shoulder in [Deewaar] was an adjustment for an error in stitching, shirt too long so knotted it".^[27] In certain scenes, Bachchan had some input on Chopra's direction, such as the father's funeral scene where Bachchan, instead of lighting the pyre with his right hand, suggests to use his left hand to show off the tattoo, "Mera baap chor hai" ("My father is a thief").^[8] The film w