Kal Ho Naa Ho is an unadapted book.
"In an extensive comparative analysis of Kal Ho Naa Ho with Siddharth Anand's 2005 film, Salaam Namaste, Cleveland State University School of Communication assistant professor Anup Kumar believes the films are similar representing "as an archetype" the "'unity in diversity'" of the characters
 He began working on the script for a film that would later be titled Kal Ho Naa Ho

