Rockinghorse Children’s Charity is to close its shop in George Street, Hove, at the end of March.
The charity’s chief executive Claire Ross-Baker said that it had been a difficult decision after two and a half years in business at the shop.
She said: “The lease for our Hove store is coming up for renewal shortly and due to the increasing costs of running a shop, we’ve decided to invest in other areas of fundraising where we can generate more income to support vital services for sick children in Sussex.
“We’re incredibly grateful to our shop managers, Sara and Melody, and to Lesley Elkin and the team of amazing volunteers who have donated their time and effort to help run the shop.
“We’d also like to thank individuals, shops and companies who have donated clothes, books and bric-a-brac, or attended shop events over the past two and half years.
“We’re confident that this is the right decision for the charity, but we’ll still be sad to see it go.”
“We want to assure everyone who has donated items to the shop that we aim to sell everything before it closes in a month’s time.
“The contributions will still raise valuable funds for children at the Royal Alexandra Children’s Hospital and our other projects across Sussex.”
The shop opened in 2009 and has hosted a number of events, including a book reading with CBeebies star Sid Sloane, a wedding dress event and an Easter egg hunt.
Rockinghorse is encouraging people to continue supporting the charity by selling unwanted clothes at car boot sales or listing items on eBay and donating a percentage of the profits.
It is also possible to recycle unused mobile phones to help raise funds.
Anyone wanting to find out more about any of these ideas can give the charity a call on 01273 330044 or visit www.rockinghorse.org.uk.
Rockinghorse, which is based in Brighton, was set up in 1967 and is best known for its work with the Royal Alex and its support for the Trevor Mann Baby Unit.
It also raises money for life-saving medical equipment in a number of hospitals and provides much-needed sensory play areas for children with disabilities across Sussex and Surrey.
Rockinghorse does not receive any government funding but relies on the support of individuals, community groups, companies and trusts.