The 29-year-old actor along with co-stars Priyanka Chopra and Ileana D'Cruz performed on the song whose first few lines are in Bengali and the rest in Hindi.
Kapoor, who plays a deaf and mute character in the Anurag Basu directed film, also performed on his famous bird dance from the film last night.
"Since we kept you waiting for so long it's time that we should entertain you now. I appologise for the delay. I am getting to talk and sing so much after a year that I am ready to do anything for you people," Kapoor said.
"The song is about how we made this film. We have released the song recently and I was completely unsure about it whether I will be able to do justice to the song. The song also features our fun on the sets and shows how we used to make fun of Ileana during the filming," he added.
Music director Pritam, filmmaker Anurag Basu and UTV managing director Siddharth Roy Kapur also performed along with the star cast of the film on 'Kyon', 'Zindagi' and 'Fatafati'.
"Barfi" hits screens tomorrow.