This paper attempts to shed some light on the primary determinants of Irish inflation. The paper begins by providing a review of the Irish literature to date. This suggests that there is little agreement on the main causes of inflation in Ireland. This paper attempts to address this issue directly. This is achieved by formulating a model for both the traded and non-traded sectors of the economy. Consumer prices were thus decomposed into their traded and non-traded components. The traded sector tests the small open economy assumption whereby traded prices are determined by foreign prices and the exchange rate in the long-run. Absolute purchasing power parity (PPP) states that the price of a basket of goods in one country will equal the price of the same basket of goods in a foreign country converted at the relevant nominal effective exchange rate. This assumption was not rejected by the data and a strong relationship was found to exist. The non-traded sector examines the domestic causative factors affecting inflation whereby non-traded inflation is modelled as arising from a mark-up behaviour over wages adjusted for productivity. In this case the Balassa-Samuelson effect was evident as higher demand in the non-traded sector led to increased wages. Wage/price equality was not rejected by the data. The results for the traded sector demonstrated that a half life of deviations away from equilibrium would take approximately 14 quarters. The corresponding adjustment in the non-traded sector would take approximately 4 quarters. Both models were used for forecasting purposes and were found to provide reasonable and accurate forecasts.