Karan Kapoor and Rhea Prakash meet for the first time in a flight bound from Delhi to New York. They just cannot stand each other: Rhea is disgusted by Karan's flirtatious mannerisms and Karan is frustrated because of Rhea's overt seriousness. They have a massive fallout and part ways, vowing never to see each other's face again. Destiny brings them together again at Rhea's marriage ceremony three years later and the mars vs. venus war continues. Rhea gets married and leaves for USA. Four years later, Karan has become a successful cartoonist and travels to...

Karan Kapoor and Rhea Prakash meet for the first time in a flight bound from Delhi to New York. They just cannot stand each other: Rhea is disgusted by Karan's flirtatious mannerisms and Karan is frustrated because of Rhea's overt seriousness. They have a massive fallout and part ways, vowing never to see each other's face again. Destiny brings them together again at Rhea's marriage ceremony three years later and the mars vs. venus war continues. Rhea gets married and leaves for USA. Four years later, Karan has become a successful cartoonist and travels to Paris to visit his father. Co-incidentally he meets Rhea again and learns that her husband is no more. Karan tries earnestly to bring happiness back in Rhea's life by promising her mother that he will find a suitable groom for Rhea but the duo never realizes that they are drawing closer to each other. Will love happen? And if it does, will the star-struck couple ever admit to it? Watch the breezy romantic musical comedy Hum Tum for the answers.

Rishi Kapoor plays Saif's father and sings a song while at the Paris airport. The song, "Mai Shyer To Nahin" (I am not a poet) is from his famous movie Bobby (1973), as are many other inside jokes in the movie.


When Rishi Kapoor meets Kiron Kher, she says her nickname is Bobby. He says, "Why don't I call you Dimple?" The eponymous female lead in Bobby (1973), was played by Dimple Kapadia.


The film is loosely based on the plot of When Harry Met Sally... (1989)....

Rishi Kapoor plays Saif's father and sings a song while at the Paris airport. The song, "Mai Shyer To Nahin" (I am not a poet) is from his famous movie Bobby (1973), as are many other inside jokes in the movie.


When Rishi Kapoor meets Kiron Kher, she says her nickname is Bobby. He says, "Why don't I call you Dimple?" The eponymous female lead in Bobby (1973), was played by Dimple Kapadia.


The film is loosely based on the plot of When Harry Met Sally... (1989). However, Aditya Chopra had announced earlier that he planned on making a remake with Shahrukh Khan and Kajol in the lead roles supported by Rani Mukherjee. This was subsequently made.


Saif is wearing his own camo-printed pants in the "Ladki Kyon Na Janne Hai Ladke Se Nahin Ho Tahi" (why are girls not like boys) song.


Vivek Oberoi was chosen to play Karan Kapoor, but he declined. Aamir Khan and Hrithik Roshan were also offered the role respectively, but both of them declined too.


When Saif was trying many different hair styles for this movie, one of the assistants said for one hairdo, "This looks like a Tom Cruise style". Director Kunal Kohli heard this and included it in the script. Saif thought that it was too childish, but later Kunal was able to convince him


During the car ride after Mihir (Jimmy Shergill) picks up Bobby (Kiron Kher) and Rhea (Rani Mukherjee) from the airport, you can hear the song Andekhi Anjaani in the background. The song is from director Kunal Kohli's debut movie Mujhse Dosti Karoge! (2002) which also starred Rani Mukherjee.


Lara Dutta was offered a cameo in the movie, but was busy shooting for Khakee (2004).