About 1,000 Will County workers are on strike.
Anders Lindall, a spokesman for the American Federation of State, County and Municipal Employees Local 1028, said employees began walking picket lines at about two dozen locations Monday morning.
Lindall said the strike involves more than half of Will County's workers, including workers in the health department, nursing home, highway department, sheriff's office, court system and the jail.
The two sides have been negotiating a contract for about 15 months, but talks last week didn't produce a contract. The two sides are disagreeing over pay and health insurance payments.
A federal mediator has been assigned to the dispute for months and could call the sides back together to avert a strike.