Karan Johar had written the script with his friend Kareena Kapoor in mind as the leading lady. But she asked for too high a fee and was replaced by Preity G Zinta.
Portions of the film were shot in Toronto because of escalated production costs from filming in New York City.
Unlike many other Bollywood productions, the filmmakers actually complied with international copyright laws and bought the license to the rights to Roy Orbison's "Pretty Woman," which is featured in the film.
Abhishek Bachchan and Vivek Oberoi were approached for Saif Ali Khan's role.
Four days after the shooting began, Shah Rukh fell ill and was almost about to quit the movie. But Nikhil Advani convinced Karan to wait for him to recover before restarting the shooting again. Khan's illness lasted for six months.