The 34-year-old has not played for the Baggies since January due to a serious knee injury but is set to return to training later this month.
Baggies boss Steve Clarke told the club's official website: "It's great to have Zoltan on board for another season. He's a top professional and good within the group.
"I believe his form last season before his injury was as good as at any time in his career and our main aim is to get him back to that level as quickly as possible.
"If he reaches that level again, he will be a great asset for us."