The eurozone's inflation rate fell to 0.8% in December, official figures have shown, down from 0.9% in November.
The Eurostat data means that the inflation rate has moved further away from the European Central Bank's (ECB) target of just below 2%.
In November, the ECB cut its benchmark interest rate to a record low of 0.25%, reflecting the low inflation outlook.
The ECB will gather for its latest meeting later this week, although no changes to policy are expected.
The data may fuel concerns that the eurozone risks a period of deflation, in which consumers delay purchases in the expectation that prices will fall further.
Last week, ECB president Mario Draghi said there were no signs of deflation or an urgent need for another rate cut. But he added that it was important that inflation did not get stuck permanently below 1%.
Peter Vanden Houte, ING's chief eurozone economist, said: "Today's figures show that it's too early for the ECB to become complacent about deflation risks, especially in peripheral countries."
Eurostat also released industrial producer price data for November, showing a 0.1% fall on the month after a 0.5% drop in October.
