Fire and Emergency Services were called to the Pātea Early Childcare Centre known as Ngati Pātea Kohanga Reo in the early hours of Sunday morning.
The Dorset Street Centre was ablaze when the Fire Department arrived and further units were called in to assist.
A Fire and Emergency spokesperson said the fire was extinguished with the help of three fire appliances within two hours of arrival.
An investigative unit was dispatched and visited the building today. The cause of the blaze is unknown at this stage and further investigations are underway.
A police spokesperson said Police were called about 12:35am to a building fire on Dorset Street and are assisting FENZ with enquiries into the circumstances.