The gala, which funds AIDS research, is hosted every year on the sidelines of the French film festival.
Abhishek, 38, tweeted that he had joined his wife and daughter Aaradhya in Cannes.
"No matter how tired you are, seeing the family and holding them in your arms is the greatest cure for any fatigue!
"Tonight to the 21st annual Cinema Against AIDS event with the Mrs to support @amfAR's mission to find a cure for HIV. #amfARCannes," Abhishek posted.
Abhishek flown down to the 67th Cannes Film Festival on May 21 after finishing Pro Kabaddi League auctions in Shimla.
Held at the Hotel du Cap-Eden-Roc, the evening will be attended by some of the biggest names from the world of fashion, music and business including Sharon Stone, Heidi Klum, Carla Bruni-Sarkozy, Kenneth Cole, John Travolta and Kelly Preston and Harvey Weinstein.
Singers Robin Thicke, Lana del Ray and Aloe Blacc are performing at the event.