Sivaraman, unable to find a good job, joins a colony as a security guard, identifying himself as Ramsingh. Geetha lives in the colony with her daughter. Geetha's husband works abroad. A police officer Rajagopal comes to the colony along with his daughter Latha. Latha is none other than Sivaraman's ex-lover. A flashback is shown where Sivaraman and Latha are classmates and in love with each other, but Latha breaks up after a misunderstanding.
Seeing Latha after a long time, Sivaraman gets excited but Latha does not reciprocate. Geetha finds Sivaraman's real identity and treats him with respect, while other colony members ill-treat him as he is just a security guard. The colony members also spreads rumours about Ambika having illegal affair with Sivaraman. Anand, a cunning guy lives in the colony and sets an eye on Latha but gets beaten up by Sivaraman. Now the colony members turn against Sivaraman. But Geetha comes to Sivaraman's rescue. Latha also understands that Sivaraman is still in love with her and decides to patch up with him.
Geetha's husband comes from abroad. The colony members speak ill about Geetha to Ramesh. But Ramesh does not believe those and trusts Geetha. It is revealed that Geetha has already informed Ramesh about Sivaraman, and Ramesh has also arranged him a job abroad. The movie ends on a positive note with Sivaraman and Latha uniting.
Annanagar Mudhal Theru was released on 14 January 1988.[7] The following week, N. Krishnaswamy of The Indian Express praised the performances of Janagaraj and Sathyaraj, but noted that, slowly the film "belies its distinctive start and sluds into tiresome cliches so well-beloved to Tamil cinema."[8]Jayamanmadhan of Kalki gave a mixed review for various aspects, including the editing and inclusion of ingredients not relevant to the story.[9]
