Around 70 orderlies at Waikato Hospital will be striking on Thursday morning.
They are angry at being locked into a wage freeze as well as feeling like they have lost conditions.
Unite Union spokesman Ross Crook says they realise it's Christmas but they want to highlight that it's not going to be an easy one for them.
He says the orderlies have a special case because of the loss of wage relativity compared to other roles in the hospital.
The strike will be held between 8.30am and 12.30pm.