There is a growing awareness of the need to develop a more rational structure for scientific decision-making in the environmental sphere. The aim of this paper is to present an outline to a system for ecosystem indices (or indicators). This work is based on a holistic ecosystem perspective and the aim is to present an overall concept rather than practical results. One of the purposes of ecosystem indices is to give politicians and the general public a more easily understandable account of the environmental status and how it changes. An ecosystem index should be not only simple and concise, scientifically relevant and practical, but also economically feasible. This approach uses several important concepts, like target organisms, target ecosystems, environmental sensitivity, and environmental cost/benefit analyses related to remedial measures. Some of the ideas brought forward in this work may be unrealistic because of the complexities involved in establishing simple, practical and meaningful ecological indices. Still, the benefits of establishing even crude environmental indicators for certain ecosystems are so great, that this path is well worth pursuing.