Alain Soliveres, from the acclaimed Taillevent restaurant in Paris, Jean-Michel Lorain and Michel Trama bowed out of the April 5 culinary event, saying they found it morally objectionable.
Organised by Lebua hotels and resorts, participants were to sit down to a $29 000 feast after being flown to Surin province to witness the plight of elephants and struggling local residents.
Last year, Lebua donated nearly $60 000 to charity to silence critics who labelled the meal an unnecessary display of excess in a country where many still live in dire poverty.
But the chefs said no money would be going to charity this year.
"This is contrary to their sense of morality and they have decided to cancel their participation in this dinner," they said in a statement.
Soliveres has been awarded two stars by France's gastronomic bible, the Michelin guide, while Lorain and Trama have three stars.
Deepak Ohri, managing director of Lebua hotels and resorts, said earlier this week he hoped the event would spark an altruistic streak among the assembled bankers, casino magnets and real estate moguls.