Union members who carry out xrays, images and scans are to strike at Nelson hospital from 4.30pm on Friday afternoon until 8am on Monday over their pay.
The strike will affect all radiology services at Nelson hospital and almost all at Wairau Hospital in Blenheim.
Radio New Zealand's health correspondent says it is part of ongoing industrial action by radiographers at most hospitals around the country.
The DHB employs 47 radiographers.
Ultrasounds are the only radiology services available at Wairau hospital over the weekend.
Strikes by radiographers have been going on for eight weeks.
Xray services are also being totally withdrawn at Masterton hospital from 5.30pm on Friday until 8.30am on Monday.