Director Kunal Kohli sent Aamir Khan and Kajol a draft of the script, hoping they would agree with each other. His plan backfired: each of them sent revised versions of the script, with their own little adjustments, which included more depth and flesh to their own characters and less to the others.
The word Fanaa is an Urdu word of Arabic origin which means "annihilation". In Sufi tradition, it also means ceasing to exist.
Lara Dutta admitted that she only accepted the film so she could get into the good books of Yashraj Films as well as having the opportunity of working with Aamir Khan and Kajol. She would later act in Jhoom Barabar Jhoom (2007) which was produced by Yashraj Films.
Kajol's comeback film after her maternity break.
The film was shot in Poland because Kajol refused to shoot in the valleys of Jammu and Kashmir fearing terrorist attacks.