G.K Rayudu (Kamal Haasan) is a corrupt Mayor, and along with his assistant Tripathi (Charan Raj), takes a bribe, sells a market to a rich businessman, and forces the poor people doing business in the land to move out, threatening physical harm. Although Rayudu is married to Janaki (Srividya), he has a mistress. Rayudu knows that an investigative journalist Sandhya (Vijayashanti). He and his henchmen go to her place to destroy the evidence. She reveals to Rayudu that his mistress and Tripathi are married and have been cheating him out of his money for a long time. He finds Tripathi’s stash of diamonds and takes it. After spending some time with his wife and kids, Rayudu gets a change of heart and decides to expose his and Tripathi’s illegal activities. Before he leaves, he hides the diamonds inside one of his children’s toys. Tripathi finds out, murders Rayudu in a fit of rage, and stores the body in a cold storage.

Panicking that soon people will realize that Rayudu is missing, Tripathi notices Rayudu's younger lookalike Chandram (Kamal Haasan) in a mental institution. Deducting that Chandram is faking his mental breakdown to beat a murder charge and avoid jail, they blackmail Chandram into playing Rayudu until a major deal is completed, and Tripathi gets a lot of money. Chandram is promised freedom if he is successful. Chandram learns Rayudu’s speech and mannerisms, and with heavy prosthetics and makeup, he becomes a suitable double for the Mayor.

Sandhya is trying to expose Rayudu for his illegal activities, but she hasn’t found any real evidence yet. As she almost comes close to exposing Chandram's identity mistakenly, Tripathi sends goons to kill her. Chandram, having heard this, removes his disguise, sneaks out, and saves Sandhya from the goons. When Sandhya gets suspicious about the resemblance between him and Rayudu, Chandram lies that he is Rayudu’s son who doesn’t like his father’s illegal ways. Tripathi's search for his diamonds using Chandram proves futile.

Sandhya decides to charm Chandram to get real evidence of Rayudu’s illegal activities, so she flirts with him, and they try to meet many times. This leads to hilarious situations in which Chandram has to sneak out without Tripathi’s knowledge. Tripathi tries to kill Sandhya one more time. Chandram saves her again, but his cover is blown. Both are on the run from the corrupt police and Tripathi.

Chandram finally reveals the truth about his murder charge to the reporter. He used to be a singer and dancer. A contractor named Vallabha Rao (Gollapudi Maruthi Rao) helped him and his female dance partner become famous invites them to a hotel room. While Vallabha Rao sends Chandram on an errand run, he brutally tries to rape the female dancer and murders her. He uses his influence to put the blame on Chandram. Chandram is found guilty, but during trial, he fakes mental retardation and is put in the mental institution. Sandhya and Chandram then falls for each other. Tired of running, they hatch a plan to stop Tripathi and Vallabha Rao, who also happens to be the assistant’s partner.

Chandram goes back to the crowded market that he sold in the beginning of the film and proclaims that he will give the land back to the people and expose illegal activities he had committed with Tripathi in a big public gathering soon. Tripathi realizes that if he killed Rayudu, he would become the first suspect. He searches for a way to get the upper hand. He traces down Chandram’s mother (Dubbing Janaki), kidnaps her, and uses this as a leverage to blackmail Chandram into not doing anything silly at the public meeting.

The day before the meeting, since Rayudu's children wanted to spend time with their father, Chandram impersonates Rayudu and plays with the kids. He accidentally finds the diamonds and leaves clues so that the children could find it in the future.

On the day of the meeting, a huge crowd is built up to hear the speech and it is attended by prominent ministers. Chandram, impersonating Rayudu, is being held on a close watch by Tripathi. With the help of Sandhya and her father (P. L. Narayana), he finds the location where his mother is being held captive by the corrupt politician who had sent him to jail. He weasels into the car of a prominent minister who asks the assistant to use a different vehicle. Finally free from the assistant’s view, Chandram uses the opportunity to leave and rescue his mother, and the corrupt politician is killed in the process. Chandram comes back to the minister’s vehicle just in time as the vehicle reaches the press conference, so Tripathi does not suspect anything.

During the press conference, Chandram details all the illegal activities he had committed along with Tripathi and other politicians and businessmen with evidence. Just as he finishes his speech, he is shot by an unknown assailant. Chandram turns to Tripathi and blames him before he collapses and dies. The crowd of people becomes agitated and beats Tripathi. An ambulance comes and picks up Chandram's body.

In the ambulance, Chandram gets up seemingly unharmed. The ambulance is driven by Sandhya's father, who was the unknown assassin. The faux assassination was a distraction to let everyone think that Chandram/Mayor is dead. They then reveal the real body of Rayudu inside the ambulance. They drive the ambulance into a power grid after jumping out of the vehicle. The ambulance explodes with the Rayudu's body inside. To everyone's concern, Rayudu was killed by Tripathi during the press conference. Chandram then walks away to start a new life with Sandhya.

• Kamal Haasan as Mayor G. K. Rayudu and Chandram (Dual role)
• Vijayashanti as News reporter Durga
• Srividya as Janaki, Wife of Rayudu
• Nagesh as Minister
• Charan Raj as Tripathi, Assistant of Mayor Rayudu
• Jayalalitha as Veena
• P. L. Narayana as Father of Durga
• Gollapudi Maruthi Rao as Contractor Vallabha Rao
• E. V. V. Satyanarayana as Police inspector
• Charle as Mental patient 1
• Kavithalaya Krishnan as Mental patient 2
• Crazy Mohan as Mental patient 3
• Pradeep Shakthi as doctor
• Dubbing Janaki as Chandru's mother
• Kuyili as dancer in song "Nachina Food"
• Gautam Raju

This was Suresh's second collaboration with Kamal after Sathya (1988). For the scene where G. K. Rayudu has a massage, cinematographer P. S. Prakash used mask shots since there was no technical resources at that time.

Soundtrack was composed by Ilayaraja. S.P. Balasubramaniam rendered the song "Nachina Fuddu Vechani Beddu" in a deeper voice to match the character Rayudu's voice and had to undergo nodule surgery. Subsequently, all the songs were sung by Mano and K. S. Chithra for Tamil version.

Telugu version

All music composed by Ilaiyaraaja.

Tamil version^[3]

All lyrics written by Vaali.

• Kamal Haasan won Filmfare Award for Best Actor – Telugu in 1989.