The subway, buses and trams canceled all services, while courts, government offices, schools and public utilities were closed. State hospitals operated on a skeleton staff.
The strike was called by Greece's largest umbrella union, the General Confederation of Greek Labor, and the Union of Greek Civil Servants.
Flag carrier Olympic Airlines canceled more than 100 domestic and international flights on Wednesday. No other airlines were affected, according to Athens International Airport.
Taxi drivers operated normally, while intercity trains had a very limited service.
In central Athens, a total of around 2,000 protesters marched peacefully in two separate demonstrations. There were no arrests, police said.
One banner, recycled from April 25 protests against visiting U.S. Secretary of State Condoleezza Rice, invited Prime Minister Costas Caramanlis to "Go Home."
Chanting "The only law is workers' rights," protesters demanded higher wages and more jobs.
Civil servants are also angry at the governing conservatives' intention to end all newly hired civil servants' right to a job for life in planned constitutional revisions after the next general election, due by March 2008.
A law passed in December ended jobs for life for future employees in the country's ailing public corporations.
The government took a first step toward allowing public sector employees - thought to make up a quarter of the country's work force of about 4 million - to be sacked after striking a deal last year with workers at Greece's largest telecoms operator, OTE, formerly a state monopoly, the AP reports.
Bank workers, protesting against the abolition of collective wage bargaining in the sector, also went on strike with unions claiming an "almost 100 percent" participation, though some banks were open.
To understand how China will act, one must understand the logic of China's development. This logic has always been almost the same, be it the Middle Ages, or modern times