The 1979 hostage thriller set in Iran, Argo had earlier won the BAFTA and Golden Globes this year. Argo is a dramatization of and is based on a 2007 article about the "Canadian Caper", in which Tony Mendez, a CIA operative, led the rescue of six U.S. diplomats from Tehran, Iran, during the 1979 Iran hostage crisis.
After receiving the honour, an emotional Ben Affleck thanked his entire cast and crew and anyone associated with Argo.
Ben and his co-producers George Clooney and Grant Heslov were on cloud nine as they enjoyed the standing ovation while Ben thanked his wife for working on their marriage.
'It is work but it's the best kind of work and there is nobody else I would rather do that kind of work with," said Affleck.
A teary eyed Ben Affleck said: `I was here 10 years ago and I had no idea what I was doing, I was really just a kid, I never thought I would be here again. You have to work harder than you think you possibly can."
`You can't hold grudges - it's hard but you can't hold grudges and it doesn't matter how you get knocked down in life, because that's going to happen, you've just got to get back up.`
The best actor honour was however bagged by Daniel Day-Lewis for his role in 'Lincoln' where he played U.S. President Abraham Lincoln in the film.
Jennifer Lawrence clinched the Oscar for Best Actress for the film "Silver Linings Playbook."
The other winner of the night is Ang Lee who won his second Oscar for Best Directing (Life of Pi). Apart from the Best Direction award, 'Life of Pi' also bagged two more awards for Visual Effects and Cinematography ( Claudio Miranda).
The 3D film is based on a fantasy adventure novel by Yann Marte where, the protagonist, Piscine Molitor "Pi" Patel, an Indian boy from Pondicherry, explores issues of spirituality and practicality from an early age. He survives 227 days after a shipwreck while stranded on a boat in the Pacific Ocean with a Bengal tiger named Richard Parker.
The Best Foriegn film award went to French-language drama film "Amour", which is written and directed by the Austrian filmmaker Michael Haneke, starring Jean-Louis Trintignant, Emmanuelle Riva and Isabelle Huppert.
The narrative focuses on an elderly couple, Anne and Georges, who are retired music teachers with a daughter who lives abroad.
The 'Best Supporting Actor' was bagged by Christoph Waltz for his performance in the film 'Django Unchained', while Anne Hathaway carried home the Best Supporting Actress Oscar for her for a mother-turned-prostitute role in Tom Hooper's musical 'Les Miserables'.
The Oscar Winner list:
Best Picture: Argo
Actor: Daniel Day-Lewis, Lincoln
Actress: Jennifer Lawrence, Silver Linings Playbook
Directing: Ang Lee, Life of Pi
Supporting Actor: Christoph Waltz
Animated Short Film: Paper Man
Animated Feature Film: Brave
Cinematography: Claudio Miranda, Life of Pi
Visual Effects: Life of Pi
Costume Design: Anna Karenina
Makeup and Hairstyling: Les Miserables
Live Action Short Film: Curfew
Documentary Short Subject: Innocente
Documentary Feature: Searching for Sugar Man
Foreign Language Film: Amour
Sound Mixing: Les Miserables
Sound Editing: Zero Dark Thirty and Skyfall (A tie)
Supporting Actress: Anne Hathaway
Film Editing: Argo
Production Design: Lincoln
Original Score: Life of Pi
Original Song: Sky Fall
Adapted Screenplay: Chris Terrio, Argo
Original Screenplay:Quentin Tarantion, Django Unchained