The jobless rate in the 17 countries that use the euro rose to 10.7% in January, while December's figure was revised up from 10.4% to 10.6%.
There are now 16.9 million people out of work in the bloc, Eurostat said.
In Italy, the unemployment rate rose to 9.2% in January, the highest since monthly records began, the national statistics agency Istat said.
Italian unemployment had stood at 8.9% in December, but it is now at the highest rate since the first quarter of 2001, as the country finds itself in a second recession in four years.
Spain continues to have the highest unemployment rate in the euro area at 23.3%, while Austria has the lowest at 4%.
In itslatest unemployment report, Eurostat said the unemployment rate in the 27 EU countries reached 10.1% in January, with a total of 24.3 million people out of work.
December's jobless rate was also revised up from 9.9% to 10%.
The data comes a day after the European Central Bank (ECB) said it had provided a further 530bn euros ($713bn; Â£448bn) of low-interest loans to 800 banks across the EU.
The announcement appeared to have been welcomed by the market, with banking shares rising strongly on Wednesday.
But Steen Jakobsen, chief economist at Saxo Bank, said: "Despite the euphoria in the banking sector following the ECB's loan programme, the real economy remains very depressed and the key factor is the unemployment rate, both socially and because of the damage to growth.
"If you look at Spain's unemployment rate, it is up two percentage points in January and even Italy's rate continues to rise, so I am concerned that we really are lacking the fundamental reforms needed for growth.
"There's a huge divergence between the feelgood factor in the stock market and what's happening in the real economy. For all the money the ECB is printing, there isn't yet a big boost for companies in terms of credit."
Meanwhile,separate data from Eurostatshowed that inflation in the euro area rose to 2.7% in February, rising slightly from 2.6% in January.
It marks the 15th month in a row that inflation has been above the ECB's target of just below 2%.
Howard Archer, chief European economist at IHS Global Insight, said it amounted to a "double whammy of bad news" for the eurozone.
"This is particularly bad news for consumers, as they are not only facing high and rising unemployment, but also still squeezed purchasing power," he said.
"It had been hoped that eurozone consumer price inflation would be heading down markedly by now, but these hopes are being scuppered by high oil prices."
The data comes ahead of a meeting of EU leaders in Brussels, where they are set to discuss growth and jobs.

Gavin Roberts, 28, died of a brain injury on 15 June, four days after the collision on the A34 near the Compton junction in Oxfordshire.
Megan Williamson's petition calls for the speed limit to be reduced.
One month on from the crash that killed him she said "changes need to be made".
"I just knew that Gavin would not want anybody to suffer as we have," she said.
She wants the speed limit reduced from 70 mph to 50 mph, saying "people treat it like a motorway and it is a very narrow road".
"There's no hard shoulder either, so if there are any accidents the emergency vehicles find it difficult to get down there."
Mr Roberts was originally from Australia but had recently moved to Swindon where he worked for Network Rail.
On the night of the collision, a Vauxhall Corsa travelling southbound smashed through the central reservation and into the path of Mr Roberts' BMW.
Richard Hayes, the chief executive of the Institute of Highway Engineers, said Ms Williamson's suggestion would make the road safer, and called for the A34 to be upgraded.
He added: "I'm absolutely sure [the barriers] are not as integrated as they should be... and that may well be eased by reducing the speed limit."
The carriageway was closed 15 times in 2015 due to fatalities or injuries, and 56 times in the last five years, Highways England confirmed.
A spokesman said safety was its top priority, and that it monitored the A34 on an ongoing basis.
"Our thoughts go out to all those affected by the recent tragic incident," he said.
Thames Valley Police said no arrests had been made following the collision and it was still appealing for witnesses.
The unemployment rate in the eurozone continued to rise in January, hitting another record high.
[NEXT_CONCEPT]
The girlfriend of a man who died on a stretch of road where more than 50 people have been killed or injured in the last five years has called for tougher speed restrictions.