All visitors must pass through metal detection before experiencing the theme park. All bags, backpacks, purses and packages are subject to X-ray and/or additional inspection prior to entering the theme park. Coolers, suitcases and bags with wheels are prohibited.

Universal Studios Hollywood has specific bag and security policies to ensure guest safety. All bags, including purses and backpacks, must go through X-ray screening at the security checkpoints located at the entrance to CityWalk or the Theme Park. There is no official "maximum size" for a standard backpack, but extremely large suitcases or bags with wheels are generally prohibited inside the park. Crucially, many of the park's thrill rides (like Harry Potter and the Forbidden Journey or Revenge of the Mummy) do not allow any bags—including small purses or fanny packs—on the ride. For these attractions, Universal provides complimentary lockers for the duration of your ride time. If you have a bag that is too large for the standard free lockers, you may have to pay for a larger all-day locker. Outside food is generally limited to small snacks and water bottles (up to 2 liters); large hard-sided coolers are strictly prohibited from entering the park.