Systems of marine spatial planning (MSP) are now being introduced in many countries, with the intention of more rational arrangement of maritime uses and interests. It would be expected that marine conservation, especially the designation of marine protected areas (MPAs), would be incorporated into MSP. In practice, however, MSP and MPA designation are often taking place in parallel to each other, with relatively little integration between them, partly because of marine conservation's longer history and established institutional frameworks which cannot be simply subsumed into MSP processes. There are, nonetheless, a series of options available by which the two sets of process could be more closely linked. These options can be conceptualised temporally, by, for example, MSP improving the status of preexisting MPAs, or spatially, by, for example, facilitating the creation of multiple-use MPAs. These difficulties and possibilities are illustrated through two national European experiences.