There is no height requirement. My DS who was 2 at the time went down with his life vest on. My DH was at the bottom to catch him. The lifeguards never batted an eye about him being too short. At this time, he had just met the mark to ride Goofy (so about 36"). There was also no sign on the bottom or top of the slide indicating a height restriction. There are no lifeguards at the top either, so there would be no way to deny a child access. There's only red light/green light system to indicate when to go.