This paper describes the development of a set of sustainability indicators for the Cairngorms, an ecologically and economically fragile mountain area in NE Scotland. It takes as a starting point the OECD pressurestate-response (PSR) framework for environmental indicators and adapts this for application in a sustainability context. However, it is argued that indicators must be developed from an understanding of the processes that link human activity to environmental change and policy response. An expert group was assembled to identify the underlying processes and propose indicators that would be useful for the agency which has responsibilities for sustainable management of the Cairngorms. In selecting indicators a thematic approach was used in which PSR indicators were derived in the context of 18 socio-economic, environmental and institutional themes. Indicators were selected on the basis of feasibility of measurement and an informal cost-benefit analysis of the contribution of information in a policy context. It was concluded that to improve the use of indicators for sustainability assessment a greater understanding of economic-environmental processes is required, and performance indicators need to be developed which incorporate a comparison of current state with policy defined capacity criteria.