Karthik is a poor orphan who studies in Pachaiyappa's, a hobo in a rented room, travels by the bus, hangs out with a number of friends, and is the captain of his football team.

Arun, by contrast, comes from a wealthy family, studies in Loyola, drives his own car, hangs out with numerous friends, and is also the captain of his football team.

Kathir, while writing a script, "wanted some drama rather than plain love and so wrote a story of warring colleges and two boys in them".

He narrated a five-minute plot summary to K. T. Kunjumon, who was impressed with it and insisted Kathir to change the film's title to Kadhal Desam from Kalloori Saalai (transl.

[3] Abbas, then a Mumbai-based model, was in Bangalore on vacation and hanging out at a cybercafé near Brigade Road, when he bumped into Kathir, who asked him to act in his Tamil film.

[7] Kathir mentioned that he dreamt of a "beautiful place full of young people" and was inspired by College Road in Chennai,[8] with a setting by the beach which formed as "opening visual idea" for the film.

Vineeth has stated that Anand, unlike other Indian cinematographers, was able to mold actors, and would offer suggestions to him and Abbas during filming.

The soundtrack was also released in Telugu as Prema Desam and in Hindi with the title Duniya Dilwalon Ki, with lyrics written by P. K. Mishra and Mehboob Kotwal.

Rahman asked for a dummy lyric for it which started with "Inbathai karuvakkinal penn", which Vaali liked and retained it for the final cut as well.

[12] D. S. Ramanujam from The Hindu wrote "Grandiose trappings in the form of giant sets, never before erected on such a scale in an Indian movie, offer a fitting backdrop for a love story.

[14] Regarding the Hindi dubbed version, a critic from The Indian Express wrote that "It is Tabu’s lively performance that holds the film together".

[22] The climax of Kadhal Desam broke a taboo in the Tamil film industry, where a love triangle would be decided with a happy ending.

[25] "Kalluri Saalai" and the instrumental theme of the song and flowers falling on the road was parodied in Tamizh Padam 2 (2018).