The film tells the story of suyambu, a middle-class cable TV operator, and his family. They come under suspicion when Varun, the son of the Inspector-general of police (IG), goes missing soon after harassing Suyambu's daughter. The rest of the film reveals how Varun disappeared and what Suyambulingam does to keep his family from going to prison.
Suyambulingam (Kamal Haasan) is an orphan who had dropped out of school after his 5th grade. Now he is a businessman running a cable TV service in Papanasam, a small town in the Tirunelveli district of Tamil Nadu. He is married to Rani (Gautami Tadimalla) and they have two daughters, Selvi (Niveda Thomas) and Pulimeena aka Meena (Esther Anil). His only interest apart from his family is watching films. He spends most of his time in front of the TV in his small office.
During a nature camp, Selvi gets photographed in the bathroom by a hidden cell phone. The culprit, Varun (Roshan Basheer) is the son of Inspector General Geetha Prabhakar (Asha Sarath). Varun is accidentally killed by Rani and Selvi when he comes to blackmail them. They hide his body in a compost pit, which is witnessed by Meena. Rani tells Suyambulingam about the incident and he devises a way to save his family from the law. He removes Varun's broken cell phone, places the SIM card on another mobile phone which he throws onto a Mumbai-bound lorry and disposes of his yellow-coloured Maruti Zen, which is seen by Constable Perumal (Kalabhavan Mani), who has a grudge against Suyambulingam. Suyambulingam takes his family out on a trip to Tenkasi to pray in a temple, watch a movie, stay in a hotel and eat at a restaurant. Geetha, seeing that her son has gone missing, starts an investigation on her missing son.
After a preliminary investigation, Geetha calls Suyambulingam and his family for questioning. Suyambulingam, who had predicted that this would happen, had already taught his family how to change their alibi at the time of murder. When questioned individually, they give the same replies. Suyambulingam also presents the bill of the restaurant, the hotel bill, the movie ticket and the bus tickets as proof of their alibi. Geetha questions the owners of the establishments they have been to and their statements prove Suyambulingam's alibi. However, Geetha realises later that Suyambulingam had faked the evidence and established his alibi on the owners by going on a trip with his family to the same establishments later. Meanwhile, Suyambulingam tells his brother-in-law, Thangaraj (Abhishek Vinod) that if they are ever taken away by the police, he has to call the media and report about their unlawful arrests.
Geetha arrests Suyambulingam and his family and Perumal uses brute force to beat the truth out of them. Eventually, Meena gives in and reveals the place where the body is buried. After digging the compost pit, they find the carcass of a calf, indicating that Suyambulingam had moved the body. Meena reports to the media and complains against Perumal. The constable is suspended and Geetha resigns from her post.
Later, Geetha and her husband Prabhakar (Anant Mahadevan) meet Suyambulingam to ask forgiveness for their rude and violent behavior. Prabhakar asks Suyambulingam if he can tell them about their son. Suyambulingam then reveals indirectly that his family has committed a crime. Now in remand, Suyambulingam signs a register at the newly constructed local police station. As he leaves, a flashback shows him leaving the incomplete police station with a shovel in hand, indicating that he has hidden Varun's body in the foundations of the police station itself.
After the commercial and critical success of the 2013 Malayalam film Drishyam directed by Jeethu Joseph and starring Mohanlal, several regional producers approached the makers for remake rights. A Tamil version was planned to be jointly produced by Suresh Balaje, George Pius of Wide Angle Creations, Raj Kumar Sethupathy and Sripriya Rajkumar of Raj Kumar Theatre. The team subsequently signed on Kamal Haasan in late January 2014, to enact the leading role after successful negotiations, with Jeethu Joseph choosing to direct the Tamil version himself. Jeethu said that Rajinikanth was initially approached to do the lead role and although he was interested to take up the role, he had doubts regarding a few scenes and how they would appeal to his fans. The pair then chose to alter the storyline to feature a Hindu family from Papanasam instead of Christian Keralite's, to make it familiar with Tamil audiences. Jeethu further said that the Tamil version had been made "more emotional" since Kamal Haasan felt that Tamil audiences like to be "emotionally piqued". In August 2014, the film was reported to be titled Papanasam. Pranav Mohanlal joined the team as an assistant director during the film's first schedule. Jeyamohan was selected to write the dialogues for the film. Noted writer/ director Sukawho is known for his characteristic Tirunelveli based short story series called 'Moongil Moochu' that was published in Ananda Vikatan trained Kamal Hassan to speak in Tirunelveli accent.
Several actresses were considered and approached for the leading female roles, before the team made a final decision. Simran was reported to have signed the film, though she later stated that she was not working in the film. Nadhiya, Sridevi, and Abhirami were also considered for roles in the film. Joseph confirmed that Sridevi was not part of the project and that the team would make the official announcements as soon as the cast and crew were finalized. Kamal Haasan's partner Gautami was later confirmed to play Meena's role from the original in June 2014, marking her comeback to acting after a sixteen-year sabbatical. Asha Sarath was chosen to reprise her role as a police officer from the original version, while Kalabhavan Mani would portray Kalabhavan Shajon's role from the original. Niveda Thomas was signed on to play the elder daughter of the lead pair, while child artiste Esther was also added to the cast, reprising her role from the original as well. Anant Mahadevan was selected to play the role of Siddique from the Malayalam version. Roshan Basheer was also selected to reprise his role as Varun from the original.
Jeethu Joseph confirmed that shooting for the film would commence from the second half of 2014. The film kick-started with a formal pooja on 16 July 2014. Principal photography commenced on 25 August 2014. with first schedule beginning in Tirunelveli where scenes featuring Kamal Haasan and Gautami were initially shot. Shooting took place in Nanguneri and Tenkasi , kuthukalvalasai, Mekkarai, a town in the Tirunelveli district. Shooting also took place in Thodupuzha in the house originally used in the Malayalam version. The house underwent minor changes to look like a Tamil household. Working stills from the film were released on 11 September 2014.
Sathish Paul, a Malayalam filmmaker-scriptwriter filed a petition with the Ernakulam District Court asking to stop the Tamil remake of Drishyam, alleging that the original film was a copy of his story published as a book in May 2013 called Oru Mazhakalathu. Benoy Kadavan, Sathish's advocate, informed that his client was told by Jeethu that Drishyam was going to be a family drama, and not a thriller. But when the movie was released, he noted that it was an exact copy and that a notice was sent to Jeethu Joseph and both the Malayalam and the Tamil production houses asking for equal shares in the profits of the film. Jeethu clarified that his story might have had some similarities with the Japanese film, Suspect X (2008), but cited that it was not a copy of any other story and was willing to move to the high court to prove it.
In mid-March 2015, it was proved at the High Court that the allegation was false, with a verdict being passed confirming the film's originality.
Ghibran composed the music for the film, with Na. Muthukumar writing the lyrics. The soundtrack, featuring two songs with lyrics written by Na. Muthukumar, six instrumental tracks from the score, performed by Sofia Session Orchestra and two karaoke tracks, was released on 22 June at a Chennai FM station.
The film released on 3 July 2015 worldwide and turned in to a blockbuster inspite of release of magnus Bahubali.
Hindustan Times gave the film 4 out of 5 and stated "A must watch for those fans of Kamal who have been waiting to see him as an actor -- not just a star driven to stunts". Deccan Chronicle gave 4 stars as well and wrote, "Riffing a sophisticated mix of the human condition and a simplistic storyline, Papanasam is a movie that engages your senses while managing to dispel any misgivings on a timely basis...director Jeethu Joseph has recreated the original magic of Drishyam but with a more localized flavor to boot". Filmibeat rated the film 4.5 out of 5 and concluded "Papanasam is a winning script and retaining Jeethu Joseph has helped immensely. But when a performer called Kamal Haasan takes up such a project, magic on screen is rest assured."
Sify wrote "the Tamil version is even tighter (than Drishyam) and there is absolutely no room for error in the writing. Flawless is the word", going on to call the film "excellent". Writing for Rediff, Sukanya Verma, while calling the film a "worthy remake of Drishyam, stated, "I still like Drishyam better but Papanasam is a laudable runner up even if somewhat self-aware".
The original story by Jeethu Joseph was released in Malayalam as Drishyam which was later remade into several Indian languages and Sinhalese language due to its immense success . The remake rights of the film were sold for ₹155 million. It was first remade in Kannada as Drishya (2014) by P. Vasu and starring V. Ravichandran and Navya Nair. The Telugu version titled Drushyam (2014) directed by Sripriya featured Daggubati Venkatesh, along with Meena reprising her role. Jeethu himself directed the Tamil remake Papanasam. A Hindi remake was also made with the same name in 2015, directed by Nishikant Kamat and starring Ajay Devgn and Shriya Saran in the lead roles. All these versions were commercially successful. It was remade in Sinhala language as Dharmayudhaya. The film was directed by Cheyyar Ravi starring Jackson Anthony and produced by MTV Channel under The Capital Maharaja Organisation Limited.