Rimutaka prison is set to open the country's first dementia unit later this year.
The Corrections Department confirmed the "high dependency unit" will be created for some of the 120 inmates aged over 65 who struggle with daily tasks, such as showering themselves.
Corrections National Health Manager, Bronwyn Donaldson, told Radio New Zealand's Morning Report she hoped the unit would be open by the year's end.
"The high dependency unit won't be, automatically at 65 - you're in. We're looking at starting it with a maximum of 20 prisoners, it's most likely to be the people who cannot do those activities of daily living themselves ... the people who struggle with showering, incontinence."
Mary More, the lawyer for one of New Zealand's oldest jailed paedophiles, said the unit was long overdue.