In this study, environmental performance of OECD countries -based on the selected environmental indicators and a target year- is evaluated by DEA (Data Envelopment Analysis) and the relative activities of these countries are interpreted within the context of existing criteria. For the dataset subject to analysis in the survey, the current EPI (Environmental Performance Index) classification is used. EPI is an important tool, created in collaboration by Yale and Columbia Universities, which has been utilized to evaluate the environmental health and ecosystem viability objectives of countries over different sets of indicators for two years since 2006. An “efficiency” assessment is made based on the relationship between inputs and outputs identified by EPI indicators. The data selected by considering the “Sustainability of the quality of life” policy principle are evaluated by being associated with the method used in consideration of the conceptual framework. The results of the study also show which countries should to take role-models in order to increase the effectiveness among the OECD countries and to make effective the countries with inefficiency scores.