This paper demonstrates an evaluation of 71 developed and under-developed countries’ biodiversity performance using a methodological framework based to the new advances of Data Envelopment Analysis (DEA). By using conditional DEA, bootstrapping and kernel density estimations, efficiency levels of 71 countries are compared and analyzed. In such a way the paper by modelling and measuring countries’ biodiversity performance analyses whether the countries environmental policies have been used efficiently in order to enhance biodiversity.