Thursday morning dozens of mental health professionals and opticians, members of the National Union of Healthcare Workers, picked up signs and joined the picket lines.
They're asking for the same level of health and retirement benefits that they and other unions currently get, and for the hospital to increase staffing levels to improve patient care.
"Last year Kaiser had layoffs for the first time since I've been here, and I've been here 13 years. Since then, there has been no hiring. No one has been hired in those positions so they are vacant, not filled and so that has caused our patients, which we serve everyday to have longer wait times," NUHW member Jim Zimbelman said.
The NUHW has the support of a much bigger union, the California Nurses Association, which just signed a 3 year contract with Kaiser keeping its members' benefits the same.
Registered nurses with the CNA said they joined the strike in sympathy with their coworkers.
The hospital disagrees with the union's claim of inequality.
"Quite frankly, we're disappointed and we're disappointed because we have a signed agreement with the CNA," Kaiser chief nursing officer Amy Tobin said.
While workers protested outside, Kaiser remained open and fully staffed. Employees say they'll go back to work tomorrow at 7 a.m., when the strike is over. Both the hospital and the union say they look forward to resuming talks.