Unemployment in Greece hit a record 25.1% in July, with the level among young people reaching 54.2%, according to the latest official figures.
Greece's statistical authority said 1.26 million Greeks were jobless in July, with more than 1,000 jobs lost every day over the past year.
With austerity cuts continuing and Greece likely to enter another year of recession, the level may rise further.
The worst-affected 15-24 age group, however, includes those in education.
According to Greece's statistics agency the total unemployment rate rose from 24.8% in June. In July 2008, a year before Greece's financial crisis broke, there were about 364,000 registered unemployed.
"This is a very dramatic result of the recession," said Angelos Tsakanikas, head of research at Greece's IOBE economic research foundation. He did not expect employment to pick up for at least a year.
The Greek economy is surviving on international bailouts, but Athens has been forced to impose tough austerity measures in return for the money.
Finance Minister Yiannis Stournaras will hold talks on Thursday evening with representatives of the European Union, International Monetary Fund and European Central Bank about signing off the release of more funds.
The BBC's correspondent in Athens, Mark Lowen, said: "The figures have bolstered the anti-austerity argument here, giving fuel to those who believe the entire strategy of Greece's international lenders is wrong, and that pressure for ever more cuts is pushing the country to breaking point and stunting growth.
"They point to the fact that before Greece was bailed out in April 2010, and began its austerity drive, unemployment stood at just 11.8%," he said.
There was some evidence on Thursday that the government's strategy is working on one front, at least. Finance Ministry figures showed that the deficit-cutting effort is on track despite lower-than-anticipated revenues.
The ministry figures showed that the January-September deficit was 12.64bn euros, lower than the 13.5bn-euro target.