Data from the Irish National Farm Survey and Census of Agriculture were used to analyse the regional implications of the decoupling of direct payments for farmers in Ireland. A mathematical programming model was used to estimate the regional effects of decoupling while a micro-simulation model was exploited to map the geographic distribution of decoupled payments. The results show that under the historical decoupling scheme, milk quota will shift from less efficient to larger more efficient farms in all regions. Beef cattle numbers are projected to decrease on all farms, with the exception of the Mideast and Southeast regions where numbers are projected to increase. The regional effect of decoupling on sheep farming was marginal with all regions projected to benefit from the policy change. The analysis also shows, using a static micro-simulation model that a shift to a flat rate national calculation of the decoupled payment would result in a significant movement of revenues from the southern regions to the northwestern regions of the country. In particular, large beef and dairy farmers in the southern regions would lose out while small dairy and sheep farmers in the western and northern regions would be most likely to gain.