In this paper the implications of ecologically sustainable economic development for modeling are considered. First we discuss the concept of ecologically sustainable economic development and suggest that any description of it should consider four central concepts: intergenerational trade-off, interregional aspects, multiple use of resources, and risk and uncertainty. We discuss each of these at a conceptual level and consider the implications for model building and model use at both theoretical and operational levels. It is concluded that, although different approaches are possible, to a large extent similar requirements for models are to be fulfilled.