Environmental resources and values (natural capital) should be seen as a key factor in regional competitiveness. However, little attention has been paid so far to the role of natural capital in the process of achieving competitive advantage from the territorial perspective. Therefore, the main purpose of this paper is to present the results of a study on the environmental competitiveness of Polish regions. The author’s contribution to the theory is the use of taxonomic metrics for research purposes. Based on certain predefined criteria the environmental potential of each voivodship was assessed in 2004 and 2012. For research purposes, 26 indicators of state, pressure, and environmental protection were proposed. Owing to the fact that the subset of diagnostic variables (indicators) contained elements that could not be directly aggregated, their unification was achieved using standardization formulas. The methodology proposed by the author might be used to assess environmental competitiveness in different regions or countries. The results of the performed analyses indicated that the Subcarpathian province scored highest in terms of environmental competitiveness, while Swiętokrzyskie province scored lowest.