Ireland with its extensive seas, belatedly being recognised as a significant development resource. There is evidence that a diverse range of stakeholders at national and local levels in Ireland are positively disposed toward MSP but no practical manifestation of the concept is in place, though some preparatory work is underway to facilitate its likely implementation into the future. Little in-depth research has been undertaken to explore how MSP could be best implemented in Ireland. The European Commission (EC) is a major promoter of MSP and has developed a set of common principles for MSP in the European Union. A critical examination of these principles in practice is undertaken through an evaluation of three marine spatial planning initiatives: The Channel Islands National Marine Sanctuary; The Clyde Pilot MSP Project; and The Eastern Scotian Shelf Integrated Management Initiative. The objective of these evaluations is to derive useful lessons regarding the implementation of these principles in general. A critical examination of the Irish context is also presented and a roadmap for MSP in Ireland is developed. It is evident that the EC's guiding principles provide a useful framework for the implementation of MSP. Some principles, however, need further clarification, elaboration and strengthening. Successful implementation of MSP in Ireland requires the development of national marine policy which creates an overall vision for Ireland's marine environment and economy and which emphasizes the place-based nature and integrated management dimensions of MSP. It also requires the development of new ecosystem governance practices and mechanisms through which stakeholders can engage in a dialogue about the management of the marine environment.