Her first movie was J. P. Dutta's Refugee which was released on June 30, 2000 and included co-debutant Abhishek Bachchan in the cast. Her other notable roles include "Pooja" in the inter-generational melodrama Kabhie Kushi Kabhie Gham, "Kaurwaki" in Asoka, the title role in Chameli, in which she plays a prostitute and her role as a riot victim in Dev.

Kareena is the great-granddaughter of Prithviraj Kapoor, the famous actor. She is the granddaughter of actor and producer Raj Kapoor and daughter of Randhir Kapoor and actress Babita. Her great uncles are Shashi Kapoor and Shammi Kapoor. Her uncles are Rishi Kapoor and Rajiv Kapoor. Her cousins are Ranbir Kapoor and Nikhil Nanda who is married to Amitabh Bachchan's daughter, Shweta Nanda. Her sister Karisma Kapoor is also in the film industry.