The ecosystem approach to fisheries (EAF) has been developed during the last decade in response to perceived and actual deficiencies in previous methods of management. The EAF recognizes that fish are only one albeit important part of a much wider ecosystem incorporating an array of physical and biological components that humans interact with and exploit. Rather than managing single fish stocks, an EAF is concerned with the impacts of fisheries on the marine ecosystem, the interactions between different fisheries, of fisheries with the aquaculture sector, as well as with other human activities. The Geographic Information System (GIS) is considered an ideal platform upon which to perform necessary information management and decision-support analysis for the implementation of an EAF. This technical paper is primarily intended to be a guide to methods that readers could adopt for their own use of GIS for an EAF and these methods are covered in some detail. The planning considerations for an appropriate GIS in terms of objectives, scope and geographical area are outlined. The practical considerations are discussed and include hardware architecture, various software possibilities, sources and types of data that will be needed, and the array of backup and support that is available. More specifically, in Section 1 of this paper, the conceptual basis underlying EAF is discussed. In Section 2, a four-step participatory ecosystem management planning and implementation process consistent with EAF is recommended by the Food and Agriculture Organization of the United Nations (FAO) and includes: (i) scoping for issues, (ii) setting objectives, (iii) formulating rules and (iv) establishing a monitoring, assessment and review system. In Section 3, the use of GIS is examined beginning with a brief look at its history and development and then reviewing its current application and uses within marine fisheries. In Section 4, the potential use of GIS in a wide range of EAF-related projects is illustrated using examples that focus on mapping, modelling, management and communication. The degree to which GIS is currently being used for EAF implementation is illustrated by four case studies detailed in Section 5. Section 6 proposes a plan for implementation of an EAF using GIS and considers the challenges faced by developing countries in using GIS in fisheries management. Strategies to enhance the role of GIS in EAF are suggested. In conclusion, Section 7 makes recommendations for the adoption of GIS for EAF. The adoption of GIS for an EAF is no easy task and a number of challenges must be faced but GIS for EAF is feasible even in relatively resource-poor situations. The authors hope this paper encourages fishery managers and researchers to explore the many benefits of GIS for managing fisheries in an ecosystem context.