The Writers Guild of America strike had jeopardized the high-profile presentation, but the work stoppage ended this month, meaning there was no WGA picket line outside the venue and union scribes were allowed to help write the show.
"The Daily Show" star Jon Stewart is serving as the telecast's master of ceremonies.
Competing for the best picture award are the period romance "Atonement," the teen pregnancy comedy "Juno," the legal thriller "Michael Clayton," the crime drama "No Country for Old Men" and the oil epic "There Will Be Blood."
Spotted on the red carpet going into the event were Jessica Alba, George Clooney, Johnny Depp, Daniel Day-Lewis, Cate Blanchett, Forest Whitaker, Ellen Page, Harrison Ford and Javier Bardem. The glitzy crowd also included Helen Mirren, John Travolta, Steve Carell, Patrick Dempsey, Amy Adams, Julian Schnabel, Jennifer Garner, Viggo Mortensen, Hal Holbrook and Julie Christie.
Star gazers also got a glimpse of Seth Rogen, Anne Hathaway, Ruby Dee, Tommy Lee Jones, Mickey Rooney, Dwayne "The Rock" Johnson, Keri Russell, Marion Cotillard, Tilda Swinton, Cameron Diaz, Laura Linney, Sean "P. Diddy" Combs and Jason Reitman.