The challenge for implementing an ecosystems approach to environmental decision-making processes, such as spatial planning, is to understand the range, nature and amount of ecosystem services currently provided and the potential for such service provision in the future. The ability to spatially represent ecosystems services is a critical element of the evidence base on which to make decisions about how physical space is used most effectively and sustainably, and the way people and activities are distributed at different spatial scales. This paper reports on the outcomes of a research project originally undertaken for the UK Department for the Environment, Food and Rural Affairs which developed a methodology for mapping ecosystem services using GIS and readily available, existing land use/land cover datasets. Critical components of the methodology, in order to determine which datasets are appropriate for which services, are network analysis and stakeholder engagement techniques, to define the relevant typology of ecosystem services and their relationship to land use/land cover types. The methodology was developed and tested successfully in the context of green grid (green infrastructure) networks in a major UK regeneration area, the Thames Gateway, to the east of London, and its potential use in impact assessment further explored through a number of case studies.