Unusually for a work by Bhansali, there are no songs featured in this film. So the background score became of paramount importance to the composer, Monty. To create more of an uplifting aura for the deaf-blind-mute character of Michelle McNally, he used pianos and strings, but kept the voices in the chorus at a low octave. For Debraj Sehai's character, a fighting spirit needed to be vocalized, so Monty used a little-known Middle Eastern instrument called a duduk.
Snow was essential for the story, so for the first part of the shoot, the entire unit went to Simla in mid-January. It was cold but there was no sign of snow. Since the unit could not wait around, kilos of salt bags bought from the local market and snow making machines from Bombay helped complete that schedule. The shooting would be done early at 4 am. And when the locals emerged they'd be amazed to see so much snow; it looked so authentic that they would touch it to check whether it was real. Dogs would come and lick the salt. The day after the unit left Simla, it snowed heavily.
The movie's title was registered with Kumar Gaurav; Sanjay Leela Bhansali approached him and requested him to relinquish the title, as he wanted it for his movies. Kumar felt that the film was bold and path breaking and wanted to render any help that he could to the film. Hence the reason Sanjay expressed his gratitude to Kumar Gaurav in the opening credits.
At first, Rani Mukerjee refused to step in, because she felt that she was unable to play the character she was proposed
Kareena Kapoor was first signed for the lead role but was dropped due to tension with the Bachchan family.