The workers are among some 9,000 San Francisco hotel employees who have been without new contracts since August 2009. Employees at several of the hotels have carried out a series of three-day strikes to protest the stalled negotiations.
The Hilton workers are opposing proposed increases in their workloads and health care costs, and the freezing of pensions, according to Riddhi Mehta-Neugebauer, spokeswoman for the workers' union, Unite Here Local 2.
Mehta-Neugebauer said that despite the economic downturn, the hotel industry is rebounding and Hilton is unfairly targeting workers.
"This is just to send management a strong message that everybody knows that Hilton's business is coming back," she said.
She added that workers would like to get back to the negotiating table.
The hotels have claimed that in addition to a tougher economic climate, they are also facing rising health care costs.
Housekeepers, doormen, bellhops and kitchen staff are among the workers taking part in today's strike vote, the results of which are expected tonight.
The Hilton Union Square workers could approve a three-day strike similar to one they took in April, or an extended strike, Mehta-Neugebauer said.