Pushed by recognition of the problems of fragmented management and growing interest in synthetic management goals such as sustainable development, biodiversity and ecosystem integrity, ecosystem-based management is of growing intellectual and practical significance in North America and elsewhere. Ecosystem-based management has several roots: the ecosystem approaches developed in several disciplines in the 1960s and 1970s, and earlier; more general systems approaches; and regional, bioregional, watershed and integrated resource management approaches. Although building on these, ecosystem-based management is a distinct activity that also draws on and complements ecosystem science, conservation biology, and environmental planning. Ecosystem-based management seeks to transcend arbitrary political and administrative boundaries, to achieve more effective, integrated management of resources and ecosystems at regional and landscape scales. Several key components of ecosystem-based management can be identified: defining the management unit, developing understanding, and creating planning and management frameworks. This paper draws on case studies of progress toward ecosystem-based management in Canada, the USA, and Australia to highlight lessons for implementing ecosystem-based management, and the need for new goals for it, in order to foster further, future development.