Kunal started his career as a child actor appearing in the Doordarshan TV series Gul Gulshan Gulfaam (1987), directed by Ved Rahi. He made his film debut with Mahesh Bhatt's movie Sir (1993), starring Naseeruddin Shah and Pooja Bhatt.
He went on to appear as a child actor in films such as Hum Hain Rahi Pyar Ke (1993), Raja Hindustani (1996), Tamanna and Mahesh Bhatt's autobiographical film, Zakhm (1998). He received praise from audiences and critics for his role in Zakhm, where he played young Bhatt. After Zakhm, now entering class Xth having done Zakhm during his vacations, Kunal decided to take a break from films for the next six years to complete his education.
He made his debut as a leading man in the 2005 film Kalyug produced by Mukesh and Mahesh Bhatt. His 2007 releases, Madhur Bhandarkar's Traffic Signal and Dhol, were moderately successful at the box office.
His first 2008 release, Superstar, did not do well at the box office. His latest movies include Dhoondte Reh Jaaoge, Jai Veeru and 99.
Kunal is in a relationship with Soha Ali Khan, who is five years older than him. Coincidently, Soha's brother, Saif Ali Khan, was married to an older partner, Amrita Singh, who is twelve years older than Saif.