The movie is inspired by a Time magazine article about an American couple who took their daughter to Philippines to meet her biological mother.
Scenes in the movie that are depicted as taking place in Colombo, Sri Lanka, were actually shot in Pondicherry (Pudhuchery), India. The first few minutes of the film depicting the civil war in Sri Lanka were shot in the forests of Kerala
The male protagonist in the movie is a part-time author who writes under a female pen name. The dialogue writer for the movie is also a male writing under a female pen name Sujatha.
Kannathil Muthamittal was based on a short story, "Amuthavum Avanum" by Sujatha Rangarajan.
The film premiered at the 2002 Toronto International Film Festival, and was selected as India's official entry to the 2004 Cannes Film Festival.