The High School Musical actress opted for classic black but gave it a Vanessa twist by flaunting her toned tummy in a cute cropped tuxedo jacket with a gorgeous full skirt by Hugo Boss.
Vanessa, 24, kept her glossy dark locks straight and smooth (total hair envy alert!) and teamed them with dramatic smoky eyes and a perfect pink pout.
Perfect red carpet glam!
Vanessa was without boyfriend Austin Butler but had company in a string of other stars including Kelly Osbourne, Goldie Hawn and Zoe Saldana at yesterday's event for amfAR, which is an organisation dedicated to ending the AIDS epidemic.
Up next for Vanessa is brand new movie Gimme Shelter, where she plays a homeless, pregnant teenager, and - wait for it - a mini High School Musical reunion.
She'll join co-stars Ashley Tisdale, Corbin Bleu, Lucas Grabeel, Kaycee Stroh and Olesya Rulin at a charity fundraiser in Los Angeles this month which has been organised by Monique Coleman (who played Taylor McKessie) and her GimmeMo' Foundation.
Unfortunately for Zac Efron fans, he isn't able to attend but he did tweet after the announcement: "Thanks for organising the #HSMreunion @gimmemotalk! Sorry I can't be there, but I support your cause. Proud of you Mo!"