The walk on Sunday was for all generations, giving them the opportunity to walk, eat and chat together.
Dogs were also well catered for this year, with dogs treats and homemade knitted rosettes.
Di Levantine, co-founder of the trust, said: “We were delighted to see so many old friends, past committee members, patrons, Snowdrop parents and grandparents, as well as so many Snowdrop children all enjoying the Arundel Castle Park grounds.
“His Grace the Duke of Norfolk has been so kind to allow us to hold the event since we founded the charity 25 years ago. The event is a highlight for many families and they look forward to coming each year.
“Patron Nick Herbert MP was joined this year by Chichester MP Gillian Keegan. Some people came for an afternoon out and to enjoy the views of the South Downs, while others relaxed in the sun happily chatting with friends and eating homemade cake.
“From the day, we have already recorded over £6,500 being raised and we are expecting more sponsorship money to follow. The commitment from the community and businesses makes this day a truly collaborative event which creates such a unique, special atmosphere.”
Several businesses supported the charity by displaying banners.
On the day, families enjoyed eating lunch on the site as well ice creams from the Pinks Vintage van and Edgcumbes sold thirst-quenching iced coffee.
The tea tents were supported by Party on the Grass, with cakes donated by local supermarkets and Truffles bakery.
Di added: “This created a summer gathering fit for a special 25th anniversary celebration, with music by the Rafa Skiffle band.”
Each walker received a free water bottle and a finishing medal and dog biscuits were available, too.
Snowdrop supports families with nursing care at home by community paediatric nurses, who administer medications and give advice to enable families to cope with the day-to-day challenges when caring for their child who has been diagnosed with a life-threatening or terminal illness.