Natural capital contributes to the quality of life of a region in two complementary ways: first, by directly providing environmental services that cannot be imported, and second, by supplying the natural resources that, through a human controlled production process, become valuable to humans. The evolution of the combination of these two components of the quality of life determines the path of development a region takes. Environmental services also determine the ability of natural capital to regenerate itself. Ecosystems and other components of the regional natural capital produce environmental services that provide life-support functions necessary for natural capital reproduction. The destruction of this critical natural capital impairs the internal sources of improvement of the quality of life of a region, leading to a non-sustainable path of development. This article describes a model of the relationship between natural capital and quality of life that provides a stricter definition of sustainable development through explicit characterization and classification of natural capital according to its ability to produce life-supporting environmental services, by its substitutability, and by its possible reconstruction. Application of this model then shows that there are 51 possible regional development paths, only 32 of which are sustainable and only 14 of which are sustainable while also providing improvements in quality of life. Only six of these 14 sustainable development paths are attained with economic growth, however, while the other eight paths increase quality of life by increasing the production of environmental services. The model could help in the development of institutional interventions that would promote regional development paths that are sustainable.