Just because they're grown-ups (well, sort of) doesn't mean Hollywood's biggest stars can't let their inner-kid out at Halloween.
In costumes ranging from elaborate, professionally-made ensembles to outfits pulled together out of their closets, stars hit up countless Halloween parties, and RadarOnline.com has the pictures.
Kim Kardashian was a super-sexy Poison Ivy at the Midori Green party she hosted in New York. Her reality star friend, publicist Jonathan Cheban escorted Kim as Batman's sidekick Robin.
We spotted Brit socialite Petra Ecclestone all decked out in L.A. as Jessica Rabbit. Cameron Diaz stuck a few dollar bills around her waist and attended a friend's bash as a stripper.
Bette Midler squeezed into a corset to host her annual New York Restoration Project fundraiser in Manhattan. Her pal Stevie Wonder was there as a skeleton and Alan Cumming was a mouse.