Geographical Information Systems (GIS) represent a rapidly changing technology, and awareness of their capabilities outside the GIS arena has grown rapidly during the last few years. As part of a wide-ranging ecological research programme on wetlands in Environmentally Sensitive Areas (ESAs) the Institute of Terrestrial Ecology (ITE) developed a GIS for the examination of lowland wet grassland landscapes, and the potential for their restoration (the 'Wetlands GIS'). A flexible approach to the development of the GIS was necessary to accommodate changes in technology and in the needs and interests of the key 'stakeholders' in the project: the research ecologists who supplied much of the data for the GIS and the policy-makers concerned with the application of research findings to land-management problems. This paper explains the rationale behind the use of GIS in the context of ESA-management and its evolution over a three year period. Examples of output are used to demonstrate the benefits of map displays for encouraging communication between developers and users, the data-storage, handling and analytical capabilities of the GIS and its role in matching the needs of researchers and policy-makers.