Born in Shimla, Himachal Pradesh, she studied at the Convent of Jesus and Mary School, Shimla. Her real name is Preetam Singh Zinta. She comes from a Sikh family. At first she was going to do a English honours but decided to pursue psychology. She also attended Bombay University. After getting a degree in criminal psychology at the St. Bedes College, Zinta began her career as a model and commercial (ad films) actress (she was seen in Lyril's soap ad film).

Her father, Durganand Zinta was an officer in the Indian Army. Durganand Zinta died when Preity was thirteen, in a car accident in which her mother, Nilprabha Zinta was also involved. Her mother was bedridden because of this incident. Zinta has two brothers, Deepanker Zinta and Manish Zinta, a year older and a year younger respectively. One of her brothers is a commissioned officer in the Indian Army.
She is currently dating Ness Wadia, the heir to the Bombay Dyeing company.Previously, when she was not shooting she used to return to Shimla. Zinta recently moved into her own home in Mumbai, which she bought in mid-2005.