The Artist won five gongs in all. Here is the film's director Michel Hazanaviciu, winner of the Best Director Award, actress Berenice Bejo, and actor Jean Dujardin, who won in the Best Actor category.
Jean Dujardin kisses his Oscar for Best Actor.
Meryl Streep holds her award for Best Actress, which she won for her depiction of Margaret Thatcher in The Iron Lady. She last won the award more than 30 years ago, for Sophie's Choice.
Octavia Spencer gets emotional as she accepts the Best Supporting Actress award for her role in The Help.
Spencer and Streep celebrate, holding their awards.
Christopher Plummer, 82, became the oldest ever Oscar winner when he was voted Best Supporting Actor for his part in Beginners. He addressed his Oscar statuette, saying: "You're only two years older than me darling, where have you been all of my life?"
The full list of winners
Best Cinematography: Robert Richardson, Hugo
Best Art Direction: Dante Ferretti and Francesca Lo Schavo, Hugo
Best Costume Design: Mark Bridges, The Artist
Best Makeup: Mark Coulier and J. Roy Helland, The Iron Lady
Best Foreign Language Film: A Separation
Best Supporting Actress: Octavia Spencer, The Help
Best Editing: Kirk Baxter and Angus Wall, The Girl With the Dragon Tattoo
Best Sound Editing: Phillip Stockton and Eugene Gearty, Hugo
Best Sound Mixing: Tom Fleischman and John Midgley, Hugo
Best Documentary: Undefeated
Best Animated Feature: Rango
Best Visual Effects: Hugo
Best Supporting Actor: Christopher Plummer, Beginners
Best Original Score: Ludovic Bource, The Artist
Best Original Song: Bret McKenzie, Man or Muppet
Best Adapted Screenplay: Alexander Payne, Nat Faxon and Jim Rash, The Descendants
Best Original Screenplay: Woody Allen, Midnight in Paris
Best Live Action Short: The Shore
Best Documentary Short: Saving Face
Best Animated Short: The Fantastic Flying Books Of Mr. Morris Lessmore
Best Director: Michel Hazanavicius, The Artist
Best Actor: Jean Dujardin, The Artist
Best Actress: Meryl Streep, The Iron Lady
Best Picture: The Artist