Students from Rickmansworth School have helped to raise £3,000 for the Disability Recreation Unity Movement (DRUM) charity.
Pupils from the Scots Hill school performed a presentation at the Youth and Philanthropy Initiative competition.
The event was sponsored by intu Watford, which donated the prize money, as well as coming into the school to help the students with their presentation.
Anthony Smith, director of learning for Year 9, said: "It is an honour to be involved with YPI each year, inspiring young people to go out of their way to do something for others.
"Great thanks goes to intu for making it possible for us. I am very proud of our Year 9s, many of whom have been out into the community and volunteered for their chosen charity."
DRUM will use the money to fund arts and crafts, develop facilities and subsidise trips to the seaside.