The Dharma Productions multi-starrer released on December 14, 2001.
Speaking about the milestone, Johar posted on Twitter: "11 years to #K3G... can't believe it's been that long... memories and moments on set are indelible."
The filmmaker assembled a cast of some of the biggest names in Bollywood for the project: Amitabh Bachchan, Jaya Bachchan, Shah Rukh Khan, Kajol, Hrithik Roshan and Kareena Kapoor.
The movie screened recently at the Marrakech International Film Festival, attended by lead actor Khan.
The film was a commercial success in domestic and international markets, becoming the first Bollywood picture to debut in the top three of the UK box office.
In 2011, Johar indicated that he would be interested in directing a sequel.