Betty White's Star-Studded 90th Birthday

ET was on the red carpet as some of Hollywood's top stars arrived for a special birthday bash for America's comedy sweetheart, Betty White. 

Among those to stop by and share their thoughts on how Betty is continuing to stay at the top of her game -- even as she approaches age 90 -- were some fellow cast members from her show Hot in Cleveland, as well as Amy Poehler, Joel McHale, Mary Tyler Moore and Carol Burnett.

The event was held to tape the NBC special Betty White's 90th Birthday: A Tribute to America's Golden Girl, set to air on January 16 at 8 p.m. The show features star appearances from Betty's past as well as comedy sketches including some of today's hottest comedy actors.

Watch the video to hear Betty's secrets for comic longevity and to also hear her talk about her latest project, an NBC prank show called Betty White's Off Their Rockers!