Eurostat released its inflation data fort the Eurozone on Wednesday. The inflation declined to an annual rate of -0.2% in December from 0.3% in November. That was the lowest level since October 2009.
Analysts had expected a flat reading.
The decline was driven by falling oil prices. Energy prices dropped 6.3% in December.
The inflation excluding food and energy costs increased to an annual rate of 0.8% in December from 0.7% in November.
The European Central Bank's (ECB) inflation target is close to but below 2%.
These figures are adding to pressure on the ECB. Investors speculate that the European Central Bank could decide on its policy meeting on January 22 to purchase government bonds.