Nalla Thambi (S.V. Ranga Rao) is a rich farmer and lives in the village Pillayarpatti with his children Rajangam (Muthuraman) and Karpagam (K.R. Vijaya). Rajangam is married to a sophisticated lady Pankajam (Sheela) daughter of Thandavam (M.R. Radha); Karpagam is married to Sundaram (Gemini Ganesan), a hardworking poor farmer from the same village. Karpagam and Sundaram continue to live with Nalla Thambi at his request to take care of the household and the farm.
Rajangam is blessed with a baby girl Meenakshi, but her parents neglect her. Karpagam, who is childless, takes care of the child and Meenakshi starts considering Karpagam and Sundaram as her parents. Unhappy to see how Rajangam is squandering money, Nalla Thambi hands over the administration of his properties to Sundaram. Pankajam, who has ignored her child in her formative years, is annoyed with this development and at the instigation of her father, forces Rajangam to send a legal notice to his father, asking for property settlement. Thandavam creates problems in Rajangam's family by brainwashing and misleading Pankajam and Rajangam, who blindly follow his advice.
When Meenakshi (Shakila) is taken away by Rajangam, Karpagam goes into depression. Finally, Rajangam sends her back and Karpagam becomes happy. While saving Meenakshi from being attacked by a bull, Karpagam gets killed by it. Meenakshi refuses to return to her parents and opts to stay with Nalla Thambi and Sundaram. Nalla Thambi forcibly gets his son-in-law married to his friend's (V. Nagaiya) daughter Amudha (Savithri), who was a friend of Karpagam, so that the child will have a mother. Sundaram and Meenakshi do not accept Amudha. Sundaram lives in the memory of his deceased wife Karpagam, roaming around like a sage. Amudha longs for the love and attention of both Sundaram and Meenakshi. Sadness prevails at home. Meanwhile, the estranged son Rajangam and Thandavam conspire to swindle Nalla Thambi. Thandavam, frustrated with his failure to swindle the wealth of Nalla Thambi's family, decides to eliminate Sundaram and sends goons to attack him. Both Nalla Thambi and Amudha come and save him. In the process, Amudha gets stabbed when a goon tries to attack Sundaram. When she is almost dying, Meenakshi sings her favourite song and Amudha is saved. Sundaram realises Amudha's love for Meenakshi. The family unites. Thandavam is arrested and Rajangam and his wife repent for their mistakes.
[from the book Pride of Tamil Cinema: 1931 to 2013 by G Dhananjayan, Blue Ocean Publishers, 2014]