Consumer prices in Euro zone rose 4.3% in the year to September, down from 5.2 % in August, according to Eurostat, the EU statistics arm.
Report informs via foreign media that economists polled by Reuters had expected a rise of 4.5%.
Core inflation, which excludes energy and food and is closely watched by the ECB as a gauge of underlying price pressures, also fell more than expected to 4.5 per cent, down from 5.3 per cent in August.
Compared with the previous month, consumer prices in the bloc rose 0.3% in September, a slower monthly pace than in August when they rose 0.5%.