Briassoulis (2001) organized indicators of sustainable development into four groups. A first drawing from the Organization for Economic Co-operation and Development’s (OECD’s) Pressure State Response framework, which specifies indicators of pressures on environmental receptors, and of impacts on the environment and responses. A second grouping classifies indicators, according to spatial scale, as global, national and local. A third grouping concerns the environmental medium to which indicators refer, i.e. air, water, land, etc. A fourth grouping classifies indicators, according to the main dimensions of sustainability, as environmental, economic, social and integrated. In tourism, Ap and Crompton (1998) mainly categorized perceived impacts into three domains, i.e., economic, social and environmental, while developing scales of tourism impacts. Similarly, this paper attempts to investigate stakeholders’ perceptions to evaluate sustainability of an ecotourism site based on an indicator system that covers economic, social and environmental dimensions.