Greek hotel and restaurant employees walked off the job on Thursday to protest against labor reforms prescribed by the country's official creditors in exchange for bailout funds that help Greece stay afloat.
The Mediterranean country, which has signed up to three bailouts with the European Union and the International Monetary Fund since 2010, relies on tourism to emerge from a huge debt crisis.
Summer is its peak tourist season.
With about 25 million people visiting the country annually, the sector accounts for about 18 percent of Greece's economic output and employs a fifth of its workforce.
"Tourism grows on workers' backs," read a poster in Athens.
Hundreds of workers rallied in central Athens as part of the 24-hour strike against legislated reforms allowing flexible forms of work and a lower minimum wage for young employees and weakening sectoral wage agreements.
The left-led government was first elected in 2015 on a mandate to increase wages and protect labor rights.
Anti-austerity strikes are frequent in Greece but turnout in protests has been low in recent years due to despair and fatigue after seven years of austerity that have slashed incomes and sent tens of thousands out of work.
The jobless rate, at 21.7 percent in April, remains the euro zone's highest.