Ramesh Khanna, Moulee, Sathyapriya, Fathima Babu, and Madhan Bob play other supporting roles.

One day, they are assigned a job to steal a Ganesh Idol from the temple, for a man who had just moved into a new house, citing prosperity as a reason.

Radha, while spending time alone in the house with the guys, realise that they are not bad after all and develops a soft corner for Selvam and he in return, falls for her.

After her mother's death, Radha meets her father who accepts her as his daughter but has to bring her into the house as a maid.

Selvam, after reading her diary, feels pity on her and tries to change his ways by working responsibly after Radha's advice.

He encounters music director Gangai Amaran late one night and helps him repair his car.

During an award ceremony, Radha reveals that the reason for her success is not her family but Selvam and she had fallen in love with him.

Unnidathil Ennai Koduthen was set to feature Vijay in the lead role, whom Vikraman worked with in Poove Unakkaga, but production delays meant that the actor was replaced by Karthik.

[4] Karthik initially wanted to quit as he felt the story was similar to his earlier film Nandhavana Theru (1995), but after Vikraman assured him it was not, he remained.

[6] Swathi was initially approached to appear in a single song sequence for the film, but her refusal led to Anusha being chosen.

[10][11] The success of Unnidathil Ennai Koduthen later led to Karthik making a guest appearance in the Ajith film Anantha Poongatre (1999).

[13][14] The song "Edho Oru Paattu" was later adapted by Sanjeev–Darshan in the Hindi film Mann (1999) as "Chaha Hai Tujhko".

[19] D. S. Ramanujam of The Hindu wrote, "As the admiring and worshipping hero Karthik underplays his role with maturity, Ramesh Khanna evoking guffaws with his antics and utterances.