- Entered the film industry as an assistant director to Aditya Chopra in his blockbuster Dilwale Dulhania Le Jayenge (1995).
- Kuch Kuch Hota Hai (1998), his directorial debut, was a great commercial success and won eight Filmfare awards.
- Winner of four Filmfare Awards, including two Best Director Awards for Kuch Kuch Hota Hai and My Name is Khan (2011), respectively.
- Took over his father's production company Dharma Productions after his death in 2004.
- Had a minor role in Dilwale Dulhania Le Jayenge and has made several cameo apprearances as himself in Om Shanti Om (2007), Fashion (2008) and other films.
- Hosts the celebrity talk show Koffee with Karan.
- Launched his biography An Unsuitable Boy in February 2017.