Boom, released in 2003 was Katrina Kaif's first ever role in the Bollywood movie industry. She played the role of Rina Kaif, an Indian top model who accidentally gets involved in a heist gone badly, together with her friends Anu Gaekwad and Sheila Bardez, who are played by actresses Madhu Sapre and Padma Lakshmi respectively. The adventure begins when the three confront another supermodel for an incident that happened on stage. Amidst the scuffle, diamonds, hundreds of them are lost and quickly snatched people all around. They were due to be transported to Dubai where Bade Mia was waiting for them. Because of the foiled plans, the three are blamed, and have to find a way to recover the losses met by Bade and his brothers. They decide a bank heist is the only way to get out of the sticky situation.

Boom opened to mixed reviews, but it opened career doors for Katrina. Being a model at the time, Katrina Kaif was already a familiar face. But like every model knows, getting a role in a movie is what really gets you out there. Knowing that, Katrina gave the role her everything, much to the admiration of Gulshan Grover. She did not have any reservations at the time, so she did not have any inhibitions about playing the sensual scenes which made the movie a common subject among critics and viewers alike. Boom failed to live up to the expectations that were set, but it did help in giving Katrina Kaif her first steps in the movie industry. Her then life as a model helped her fit in the shoes of Rina, her role in the film was also a model.

The role of Rina Kaif in the movie was demanding, but Katrina Kaif managed to bring what she had. Considering this was her first role, her acting was not award-winning, and though it was a noteworthy performance but inadequate among critics. She was at home with the underclothes that her role Rina had to wear. Most other actresses have inhibitions on this, but Katrina decided to take up the challenge.

All in all, Boom was an okay movie, though the cast left something to be demanded with the exception of Amitabh Bachchan who played the role of Bade Mia, the underworld leader perfectly. The sensual sense that involved Katrina were the subject of much debate as initially highlighted, and these are what gained her recognition, albeit not the kind that one wants to make a career out of. In any case, after playing Rina Kaif, Katrina decided that she would not be open to other intimate scenes in her acting career.