Joining Rihanna, Lea Michele, Gwyneth Paltrow and Kelly Osbourne at the celeb-packed do, Miley stepped out in a sheer, bondage-inspired frock.
Her dress, designed by Tom Ford, featured sparkly strap detailing and see-through sleeves - and flashed A LOT of flesh!
Wearing a saucy frock didn't stop Miley hitting up the red carpet with her mum though! Trish Cyrus was there to support the star, wearing a floor-length metallic gown.
The glam bash was held to raise money for the amfAR AIDS Research charity.
Miley's set to support the cause even further - as it's just been announced that she's launching her own MAC VIVA GLAM range next year.
The campaign sees world-famous stars (including Rihanna, Lady Gaga and Nicki Minaj) front their own make-up ranges with all the proceeds going to the MAC AIDS Fund that helps men, women and children affected by AIDS and HIV around the world.
Not sure about the frock, but good work with the campaign, Miley!
What do you think of Miley's latest outfit? Tell us below as the best comment from across the site each week wins £50!