Aishwarya Rai Bachchan's role in the movie was offered to Kareena Kapoor because she was working on Bride & Prejudice (2004) and was thought to be unavailable. Later, she took the role back when Kapoor herself became unavailable due to her other professional commitments.
The entire script was written by Rituparno Ghosh in Bengali. Since Ghosh is not adept in Hindi, he sought help from theatre personality Usha Ganguly to convert it to Hindi. In fact Ganguly is said to have supplemented the main working script along with Ghosh.
The film is inspired from O Henry's short story, 'The Gift of the Magi'.
The shooting of this movie started a day in advance on Monday 16 February 2004. There was a costume rehearsal scheduled for the Monday, but since the whole unit was ready, they began shooting. A puja was performed at the NTII studio before the first take.