A new MRI machine is being installed at Whanganui Hospital, which will result in a temporary closure of the Medlab blood testing service.
The main entrance of the hospital and Medlab services will close on Tuesday, August 20 while the equipment is being installed.
A Health New Zealand - Te Whatu Ora spokeswoman said access to the emergency department would not be affected.
Medlab services and blood testing will be closed from 7.30am until 1pm.
Staff will be available to direct people on how to gain access to Whanganui Hospital while the main entrance is shut, and traffic management will also be in place.