Wanganui SPCA Centre opened its doors to the public for the first time on Saturday.
Manager Danny Auger estimated about 300 people turned up to have a look through the London St premises.
"It went really well - we were pleased," he said. "There was a huge number coming in who had never been in the centre before."
The aim was to promote the organisation and its work.
"The day was to open up the doors to let people see behind the scenes and let people know that we have nothing to hide. People thought it was great that they were able to do that."
Mr Auger said it was the first time an open day had been held in Whanganui but it would now be an annual event. "It shows people what it is that we do - for example, a lot of people don't realise we do microchipping."
A vet nurse was on hand on Saturday for people to get their pets chipped, while there were activities such as face painting, a petting zoo and sausage sizzle.
"Everybody seemed to have a great time," Mr Auger said.
The event raised more than $2000 - "which is fantastic, even though money was a secondary thing to the promotion".