Orange County Superior Court Judge Tam Nomoto Schumann said Tuesday that she is issuing a preliminary injunction preventing the city from laying off the workers.
Schumann said the city must follow proper procedures when laying off workers but didn't explain what those procedures are.
Back in March, nearly half the city's workforce received layoff notices after the city council voted to outsource their jobs.
The Orange County Employees Association filed a lawsuit to stop the layoffs.
City officials said the judge's decision still allows them to explore outsourcing options, which could then be discussed with the union.
The Associated Press contributed to this report.