The movie is partially based on writer-director Farhan Akhtar's diaries on his trips to Las Vegas, his 1996 month-and-a-half long stay at New York City.
The script and dialogues for the film were first written entirely in English.The original gang was supposed to be Hrithik Roshan, Abhishek Bachchan and Akshaye Khanna.After Hrithik and Abhishek walked out of the project, Farhan Akhtar waited almost 10 months to get an appointment with Aamir Khan to discuss the film.Akshaye Khanna was originally supposed to play Akash. But when Aamir Khan was brought on, they swapped roles.Saif Ali Khan almost quit the movie after it was decided to be made with sync sound, instead of getting actors to dub their lines.Farhan Akhtar met Preity Zinta when she first came to Mumbai for the screen test for Kya Kehna and told her that whenever he makes a film, he wanted her to be in it.That screen test for Preity was with Akshaye KhannaFarhan Akhtar, Javed Akhtar and Shankar-Ehsaan-Loy travelled to Lonavla and came back with the entire soundtrack fully composed and written in four days.In Woh Ladki Hai Kahaan, Saif was asked to wear the classic '80s Bollywood red t-shirt and white jeans, but he put his foot down when he was asked to pair it with white shoes.The idea of making a movie within a movie came from costume designer, Arjun Bhasin.Preity Zinta loved Koi Kahe Kehta Rahe so much that she insisted on being a part of it, even though her character hadn't gone to the same college as the guys.Karan Johar thought the movie wouldn't do well and that Aamir Khan had 'lost the plot' by choosing to act in it.When she first heard the script, Preity Zinta joked with Farhan Akhtar that he was making a chauvinistic all-boys film.The first scene shot for the movie was the one where Sameer tells Akash and Sid about falling in love with Pooja.Sid's long speech to Deepa about 'letting go' of Akash was a nod to Edgar Allan Poe's poem 'A Dream Within A Dream'.Farhan Akhtar was one of the assistant directors on Akshaye Khanna's debut film, Himalay Putra.Farhan Akhtar had said that he would love an all-female cast of the movie to make the sequel.Farhan thought the phrase 'pyaar ke ghaat' from Jaane Kyun sounded really funny, but his dad Javed Akhtar told him to trust him on this.In 2001, the film won National Film Award for Best Feature Film in Hindi.