Slot technicians at The Tropicana Casino and Resort have authorized a strike against the casino, which is about to be sold in a bankruptcy auction.
The 23 workers represented by the United Auto Workers are protesting the lack of a contract after more than a year of negotiations.
The technicians maintain and repair slot machines, which are the main money-makers for Atlantic City's 11 casinos.
The casino is considering layoffs and steep increases in the cost of employee health care coverage.
The Tropicana has been operating under a state conservator because its former owners were stripped of their casino license. A Baltimore company is the leading candidate to buy it in a bankruptcy court auction.
A strike would be the first involving casino floor personnel in Atlantic City since 1982. That walkout collapsed in three days and led to the demise of a fledgling union.