The jobless rate in Greece reached a record high of 28% in November, according to newly released government figures.
The rate increased from 27.7% in the previous month. For those under the age of 25, unemployment hit 61.4%.
Harsh austerity measures have led the Greek economy to shrink by a quarter in four years.
However, other economic indicators have suggested that there are signs of recovery.
The BBC’s Mark Lowen in Athens says the bleak unemployment numbers are in contrast to a message that the government has been trying to push: that Greece has turned a corner, with six years of recession due to end this year and light on the horizon.
He says the contrast with pre-crisis Greece is stark. Before the country received its first 110bn-euro ($150bn; £90bn) bailout in May 2010, the jobless rate was under 12% here.
Slight growth is expected this year and the deficit now wiped out, apart from interest payments on the bailout.
But our correspondent says that the government fears it will take a big hit in local and European elections in May.