"A Monster Calls" has won the Carnegie Medal for children's literature and the Kate Greenaway Medal for illustration at a London ceremony.
Written by Patrick Ness and illustrated by Jim Kay, the book is about a boy dealing with his mother's battle against cancer. It is based on an idea by author Siobhan Dowd, who died of the disease in 2007.
Ness won the Carnegie Medal last year for "Monsters of Men."
The BBC quoted Ness as saying Thursday night's win was "extremely humbling -- and a little unnerving."
This is the first time the same book won both the Carnegie and Greenaway medals.