The eurozone economy grew 0.5 percent in the first quarter of 2005 from the figure for the previous quarter, an initial estimate released by the EU's statistics arm showed.
The growth marked an improvement from monthly growth of 0.2 percent in the final quarter of last year, data from Eurostat showed.
Over 12 months, the eurozone economy expanded by 1.4 percent in the first quarter.
In the 25-nation EU, the economy also grew 0.5 percent in the first quarter from previous quarter, when 0.3 percent growth was registered.
Over 12 months, the region saw growth of 1.7 percent in the first quarter.
Looking ahead, the European Union's executive commission forecast that the eurozone economy would book quarterly growth in a range from 0.2 to 0.6 percent, revising its outlook down by 0.1 percentage point. It has the same forecast for the third quarter.