The East Coast Hospice had put up six signs, costing £80, on its planned hospice site off Sidegate Road near Gorleston after travellers went on the land for several days in June.
The signs were ripped down last weekend at the site. The hospice appeal plans to start construction work on a 10-bed hospice next year there.
Jennifer Beesley, chairman of East Coast Hospice, said: “We are working hard to get this hospice and then this destruction of the signs happens. It is very naughty.”
Mrs Beesley also said the charity had spent about £5,000 on dealing with the travellers’ incursion, with money spent on clean up costs and court and legal fees.
The charity has 7.54 acres of land on the Gorleston/Hopton border for the hospice.
To make a donation to support the hospice appeal call 01493 718707 or visit www.eastcoasthospice.org.uk