More than 46 years of exploration in the Irish offshore has yielded modest commercial success. However, working petroleum systems have been proven in all the offshore basins. The pace of exploration has been controlled by: (a) data quality and technological advances; (b) geological understanding and plays; (c) fiscal and infrastructural environments; and (d) international conditions. Irish offshore exploration drilling started in the Celtic Sea basins in 1970 and the region has seen a recent renewal of exploration interest, stimulated by new and much improved seismic data. In the Atlantic margin basins west of Ireland, there has been a recent significant improvement in the understanding of the geological evolution and petroleum systems, especially in the hyperextended basins such as the Porcupine and Rockall basins. Here the major targets of current exploration are stratigraphic traps at Lower Cretaceous and Lower Cenozoic levels. The application of new and innovative seismic and other geophysical technologies in a number of the Irish offshore basins has led to significant enhancement in data quality and in resolving imaging challenges. Combined with recent geological learnings, they offer renewed hope for exploration success in the Irish offshore basins.