In recent years, due to industrialization, population growth, the continuous increase in the needs of the society and technological developments, the environmental problems of the countries are increasing and the countries take the necessary measures to eliminate this problem. In this study, six different multicriteria decision-making (MCDM) models that measure the environmental performance of countries using Entropy, Gray Relational Analysis (GRA) and Multi Objective Optimization on the basis of Ratio Analysis (MOORA) methods are introduced. Criteria weights are calculated by Entropy method and environmental performance levels of countries were analyzed by GRA and MOORA methods. In addition, the results obtained from six different MCDM models are combined with a fuzzy logic-based approach and a single result is achieved. According to the results of the analysis, it is concluded that the most important criteria are forests, agriculture, and water resources; the best performing countries are Austria, Denmark and France.