It revolves around a man who escapes from his home to avoid a forced marriage, but unknowingly falls in love with the same woman.

Unknown to Chandrasekhar, Shankar plans to grab his properties by triggering Raja to leave the house.

Raja runs away and reaches Ooty, where he meets Vasu, a con artist, and despite initial setbacks both become friends.

One day, Raja sees Indhu in Ooty and gets attracted towards her, not knowing that she was the girl fixed for him by his father.

Meanwhile, at Ooty, Raja tries to impress Indhu, while Vasu is attracted towards Viswanathan's personal secretary Meena.

Doubt erupts for Raja and Vasu upon seeing Kasinathan as he spends money lavishly, compared to Viswanathan, who is very stingy.

Raja and Vasu secretly follow Kasinathan and finds the whereabouts of Viswanathan and the plan behind his kidnap.

[11] For the filming of the song "Azhagiya Laila", Rambha wore different dresses for almost every scene, in addition to wigs.

[13] According to Sundar, the film's "hide-and-seek" sequence was improvised, as the script only mentioned "Chaos in Jai Ganesh's house leading to the kidnap of Mani Vannan".

[18][19] Ullathai Allitha was released on 15 January 1996, alongside another Karthik-starrer Kizhakku Mugam, and was more successful as the latter was a failure.

After a slow start at the box office, the songs' success on television prompted audiences to visit cinemas.

[24] D. S. Ramanujam of The Hindu wrote, "A full length comedy with enjoyable scenes, thanks to the screenplay and direction of C. Sundar, keeps the viewer in good cheer in Ganga Gowri Productions, Ullathai Alli Thaa [..] the director has the uncanny knack to fit these segments in his essay and then capping them with his new funfilled ideas, like topping a giant cone icecream with choice varieties, leading to humorous confusion over identities, bunglings by silly looking assassins, abduction and amorous ways of the elders".

[25] A year after the success of Ullathai Allitha, Sundar had plans for making a sequel with the same cast returning.

[27] The success of Ullathai Allitha paved way for numerous comedy films in Tamil cinema.

Azhagana Naatkal was compared by critics with Ullathai Allitha due to its similarity in sequences and characterisations.