The Write4GOSH competition was organised by Great Ormond Street children's hospital in London.
Tom Bird, 15, from Angus in Scotland, took the overall prize with his story What Happened Next?
It reveals what happens to characters in fairytales once the tale is over.
For instance, Cinderella sets up a glass shoe factory!
What did they have to do?
The only instruction given to entrants was that the stories had to "cheer up a child in hospital".
Lots wrote about children's hospital experiences - but even more came up with Harry Potter-inspired stories about wizards and witches!