Negotiations between Kaiser Permanente and the California Nurses Association are due to begin this week.
Union bargaining committee member Katy Roemer says the big issue is patient care.
"This is about human beings who are in the hospital requiring health care and we want to give it. So we will be there fighting to make sure that we can. We are firmly on the side of our patients and we are going to fight until we get what we need," Roemer said.
Both sides are looking to iron out a new four-year contract for nurses at Kaiser's hospitals in Northern California.
The talks are scheduled for Thursday. Negotiations had been slated to open up last week, but Kaiser said it needed more time, and the talks were delayed a week.