Abstract Portman, M. E. 2011. Marine spatial planning: achieving and evaluating integration. – ICES Journal of Marine Science, 68: 2191–2200. Coastal states and nations are conducting marine spatial planning (MSP) at an ever-increasing pace. Some MSP efforts are aimed at planning areas at a subnational level, whereas others extend as far as 200 nautical miles from shore, within national exclusive economic zones. For planning of all types, but especially for planning in the marine realm, integration has become a sought-after norm now that traditional sectoral, single-issue management has not succeeded. Fisheries collapse, threats to marine biodiversity, and global climate change all support the case for greater integration in marine resource management and policy. The designation of boundaries can be related to the level of cross-sector and cross-jurisdictional integration achieved by MSP. The importance of scale and scope for MSP initiatives is examined, relating these aspects of plans and/or programmes to the levels of integration achieved, and a framework is suggested for evaluation. MSP initiatives in Portugal, the UK, and the USA serve as potential case studies for use of the framework.