Earlier this week it had just one short-term bed available, but two others should be available soon.
The number of people with dementia is predicted to increase by between 2 per cent and 5 per cent a year, according to the Whanganui District Health Board's senior older person portfolio manager Andrea Bunn.
More beds will be available in Wanganui in June through Ryman Healthcare's Jane Winstone retirement village.
Some of the new beds there will be in a secure unit for people with dementia.
They can tend to wander, and need a close watch kept on them. They can also have "difficult behaviours" and be "verbally and physically inappropriate", Ms Thompson said.
Wanganui's Fiona Donne knows about that, because her husband Peter has dementia.
"Somebody with ordinary dementia can be very stroppy, and particularly with relatives," she said.
After some difficulty, Mr Donne was found care at Wanganui's Broadview rest home and hospital - a relief to his wife because she cannot drive and could not have visited him if he had been moved outside the city.
"The care is very good. I'm very relieved that they have got an area like that," she said.
Nobody with dementia has had to leave Wanganui for care at present, Ms Bunn said.
There are a total of 81 secure care beds available in Wanganui and Marton. They are all with private providers - 20 at Springvale Manor; 26 at Okere House; 15 at Broadview; and 11 at the Edale complex.
Rules limit the number of people in a secure dementia unit to 20, though Okere House has exceeded that with 26, agreed in an arrangement with the Ministry of Health.
A national review of the 20-resident limit is due, and may change the number of residents a unit can have.