1. Imtiaz Ali initially wanted to cast Bobby Deol and Ayesha Takia as the main leads.
2. The producers had first signed Bobby Deol in 2005.
3. Bobby suggested they approach Preity Zinta. She agreed, but needed six months before she could shoot.
4. Kareena Kapoor, who was Imtiaz's first choice, told the producers she would sign the film only if they replaced Bobby Deol with her then boyfriend Shahid Kapoor. The producers agreed and replaced Bobby Deol without even informing him.
5. Imtiaz Ali only settled on Shahid Kapoor for the role of Aditya after meeting him, as he previously viewed him as a "forgettable actor".
6. The number of prints for the film across India was increased in its fourth week of release due to popular demand and the lower-than-expected performance of Saawariya.
7. The title of the film was decided by a popular vote. The other choices were Punjab Mail and Ishq Via Bathinda.
8. The option Jab We Met was suggested by Shahid’s father, Pankaj Kapur.
9. There is a Serbian song called “Nemam Elana” which is a cover of “Yeh Ishq Hai”.
10. The film won Imtiaz Ali his only Filmfare Award for Best Dialogue.
11. Hotel Decent’s receptionist was played by the film’s art director, Teddy Maurya, whose brother was supposed to play the scene but couldn’t make it for the shoot.
12. This wasn’t the only role he played in the movie. He also played the inspector on the bridge that Geet was running on after she missed her train.
13. The character of Geet was based on a talkative girl who Imtiaz Ali met on a bus in Delhi.
15. Tarun Arora, who plays the role of Anshuman in the film, had almost given up on his acting career and went to Bengaluru to open a restaurant, when the film came his way.
16. The room where Geet’s grandfather confronts Geet and Aditya in the big room with guns was almost not going to be used in the film. The 80-year-old landlady, whose house it was, allowed them to use the room only on the condition that she be introduced to Dara Singh.
17. Dara Singh wasn’t very comfortable saying the words, “Mumbai mein toh nangi ghoomti hogi” to Kareena during that scene.
18. Geet’s character made Anushka Sharma want to seriously pursue acting.
19. The Ratlam scenes were never shot in Ratlam. The scenes were shot in Lonavla, Shimla and Manali.
20. Pawan Malhotra, who plays Geet’s uncle in the film, was initially offered the role of her elder brother.
21. The story was written as a result of a writing exercise with a friend of Imtiaz Ali’s. The exercise was to combine two elements and make a story out of it. The friend suggested “a man who wants to kill himself”, while Imtiaz suggested “a girl on a train”. Though nothing came of the idea at the time, it became Jab We Met many years later.
22. Most people on the set hated the song “Aaoge Jab Tum” because they thought it didn’t fit with the youthful tone of the film.
23. According to Imtiaz, the final kiss was apparently the most difficult scene to shoot because there was a honeycomb filled with bees right above Kareena’s head, some of which had already bitten some of the crew.
24. The film was remade in Tamil in 2009 as the film Kandhen Kadhalai, starring Tamannaah as Geet.
25. Shahid Kapoor travelled in Mumbai’s local trains to promote the film.
26. Imtiaz Ali was never confident about the film and its script. He thought it was a very thin storyline.
27. Due to a tight budget and other constraints, Imtiaz Ali didn’t have time to write the dialogue before they started scouting for locations for the film. He ended up getting stuck during a snowstorm in Manali and writing the dialogues because there was nothing else they could do.
28. The opening lines of Singh is Kinng’s hit song “Teri Ore” were actually a part of Jab We Met’s “Tum Se Hi” before they got rejected.
29. Irshad Kamil was once told by a fan that she sang "Tum Se Hi" as a bhajan every morning.