Photographers swarmed Ayush Mahesh Khedekar, Azharuddin Mohammed Ismail and Rubina Ali as they arrived at Hong Kong's international airport, with 10-year-old Azhar riding on their baggage cart.
A guardian shooed away reporters, but 9-year-old Ayush - whose movie character famously jumps into sewage so he can rush to an Indian film star to get his autograph - said he wanted to visit Hong Kong Disneyland.
The children are due to sing and dance at a live broadcast Saturday to raise funds for the Hong Kong charity The Community Chest.
"Slumdog Millionaire" is about an orphan from Mumbai's shantytowns who wins the Indian version of "Who Wants to Be a Millionaire."
British director Danny Boyle cast real-life slum residents Azhar and 10-year-old Rubina in the film. Ayush did not grow up in the slums.
But some critics have accused the filmmakers of exploiting Azhar and Rubina, and efforts to improve their living conditions have been complicated by the changing demands of their families and jealousy from their neighbors.
Fearing that a lump-sum payment would be squandered, the filmmakers set up a trust fund for the two children. They also donated $747,500 to a charity devoted to improving the lives of Mumbai street children.
The two children's shanties were razed as part of a city slum-clearing campaign, but the filmmakers and Indian government officials have promised them new homes.
Community Chest publicist Louie Tong said the charity is covering the children's travel expenses and lodging at a luxury hotel, but it is only paying them a small honorarium. She would not reveal the amount.
"Slumdog Millionaire" won eight Oscars in February - including best picture and best director - and made more than $350 million worldwide.
(This version CORRECTS second reference to Tong in graf 10.)
Copyright 2009 The Associated Press.