There are princesses, monsters, pirates, and even crime-fighting superheroes.
Whatever they choose, the point of a sugar-crazed, costumed holiday is to have them squeal with delight, not scream all the way to the emergency room.
According to the U.S. Consumer Product Safety Commission, bad falls are a big reason kids end up in the hospital on Halloween instead of counting their candy.
"Make sure they're not tripping over the bottom half of the costume, and make sure they have shoes they can run in," said Dr. Ellen Rome of Cleveland Clinic.
Visibility is key.
Experts recommend making sure masks have big enough eye holes so kids can clearly see where they're going.
Flash lights, glow sticks and reflective tape on costumes can also help cars see little trick-or-treaters after dark.
Federal law states that all Halloween costumes and Halloween accessories sold in the U.S. must be flame resistant.
But that doesn't mean they can't catch fire.
The experts recommend costumes that fit well, without billowy sleeves.
They can easily ignite on jack-o-lantern candles.