They spend their free time helping at events, baking cakes, and running raffles.
Without them, one of Bath's best-loved charities would be lost.
To show their gratitude, staff from the Forever Friends Appeal at the Royal United Hospital invited its volunteers to a party at the Bathwick Boatman.
People aged 24 to 85 attended the event, and were joined by appeal president Jeff Manning and chairman John Cullum.
During 2013 the appeal welcomed several new volunteers, who have helped on events such as the Walk of Life, and Movie by Moonlight.
Others spend their free time selling raffle tickets and distributing collection tins.
On International Volunteers Day, the appeal felt it was the perfect time to acknowledge the support and dedication of the team.
Appeal head of fundraising Tim Hobbs said it had been "a truly incredible" year for the appeal, following the "wonderful" £4-million donation for the RUH's new cancer centre from inventor Sir James Dyson and his wife Deirdre.
"We are therefore so keen to recognise what a superb job our volunteers do.
"They are all extremely valued members of our team and I want to take this opportunity to say a heartfelt thank you to them all for everything they do to help us achieve our fundraising goals.
"We simply couldn't do it without them."
Volunteers were out on the streets of Bath during the Christmas light switch on collecting donations last month.
The appeal was chosen as the nominated charity for the switch on, and raised £1,000.
People are now being encouraged to buy a raffle tickets for £1 to be in with the chance of winning a brand-new Kia Picanto
Other events over the festive period include a concert on Wednesday with the Bath Spa Band and Royal United Hospital choir at St Michael's Without Church, on Broad Street.
Tickets are £6 and are available by calling 01225 825900.
To find out more visit www.foreverfriendsappeal. co.uk.
