Grand-daughter of Indian freedom fighter, lawyer, and former Justice Rajni Patel, Amisha, a Gemini, was born in Bombay's Breach Candy Hospital. She is nicknamed Angel and Princess. Her younger brother Ashmit Patel is also a Bollywood film actor and her name is a blend of the first three letters of her father's name Amit and the last three letters of her mother's name Asha.

She studied at the Cathedral and John Connon High School in Bombay, and went on to obtain a degree in Economics from Tufts University in Medford, Massachusetts, U.S.A. After graduation she worked for a Finance company and also modeled on the side.