AR Rahman won for best original score and best original song
India has been revelling in Oscar night glory, with the success of Slumdog Millionaire, its composer AR Rahman and the documentary Smile Pinki.
Rahman won two Oscars, best original score and best original song - Jai Ho - with fellow Indian Gulzar.
Resul Pookutty bagged another award for sound mixing of the rags-to-riches Mumbai movie, which also won best picture and best director.
Smile Pinki, about an Indian cleft-lip girl, won best short documentary.
The success of Slumdog sparked massive celebrations back in the Mumbai slum where two of the film's child actors still live.
Rubina Ali and Azharuddin Ismail were both in Hollywood for the ceremony.
Indian Prime Minister Manmohan Singh said of the winners: "They have done India proud."
'Power of hope'
India's biggest winner of the night was Rahman, 43.
He said as he accepted the award: "I just want to thank again the whole crew of Slumdog Millionaire, especially [director] Danny Boyle, for giving me such a great opportunity."
INDIA'S OSCAR WINNERS
2009: AR Rahman - best original score
2009: AR Rahman and Gulzar - best original song
2009: Resul Pookutty - sound mixing
1992: Satyajit Ray - lifetime achievement
1983: Bhanu Athaiya - costume design (Gandhi)
The composer said he hailed "all the people from Mumbai and the essence of the film, which is about optimism and the power of hope and our lives".
He went on: "All my life I've had a choice of hate and love. I chose love and I'm here. God bless."
TV pictures showed Rahman's family cutting a cake in his home city of Madras (Chennai) in southern India and celebrating the composer's win.
A local band played a tribute to the composer singing Jai Ho.
Resul Pookutty won for sound mixing of Slumdog with Ian Tapp and Richard Pryke.
Pookutty said: "I'm the first Indian technician to be nominated for an Oscar and winning one... And it's an absolute glory for me myself personally and for my country."
Pookutty, a graduate from the prestigious Film and Television Institute of India, has been in the industry for more than 10 years and has worked on several big films.
A spokesperson for Indian President Pratibha Patil, said she was "specially thrilled with the remarkable feat achieved by AR Rahman, Gulzar, Resul Pookutty and making India proud".
Bollywood actor-director Aamir Khan said he was also "thrilled" by India's successes at the Oscars.
"It is great to see Indian talent [in cinema] being recognised internationally. We are no less than anybody else," Khan told TV channels.
Smile Pinki is the story of a girl with a cleft lip
Smile Pinki, a 39-minute documentary by American director Megan Mylan on an eight-year-old Indian girl born with a cleft lip, had been one of the four short documentaries nominated for the Academy Awards.
There were celebrations in the north Indian village in Mirzapur district where Pinki lives, the BBC's Geeta Pandey says.
The girl's uncle said several hundred people took part in a procession, chanting "Bharat mata ki jai" (Long Live Mother India).
One of the other films nominated in the short documentary category was also India-based. The Final Inch by American director Irene Taylor Brodsky follows polio workers across India as they vaccinate children in an effort to eradicate the virus.
India now has five Oscar winners.
Costume designer Bhanu Athaiya won for her work in Gandhi in 1983 and director Satyajit Ray won a lifetime achievement award in 1992.