The Central Statistics Office said prices had fallen by 4.7% in the 12 months to May.
Prices are dropping as the economy continues to adjust to the rapid changes which are happening in Ireland.
A big factor has been a series of interest rate cuts by the ECB, with mortgage interest down a massive 42% over the past year. In that time rents have fallen 16% and they dropped another 3% last month.
The price of computers has fallen 23% over the past year and car prices have dropped 5.5%
However, rising oil prices are being felt on the forecourts. Petrol rose 3.3% last month and diesel climbed 0.9%.
Many of the changes revealed today show businesses are cutting prices and that some sectors of the economy are becoming more competitive after the boom.
Consumer prices compared to other countries using the euro have returned to levels last seen six years ago.
