The Bern Convention aims to conserve wild flora and fauna and their natural habitats, especially those species and habitats whose conservation requires the cooperation of several states. Turkey became a party to the convention in 1984 and therefore made it binding in terms of domestic law. It was sought to answer the question of how effective the Bern Convention was in Turkish legislation and judicial decisions. For that purpose, first, comparison of the provisions of the Bern Convention with Turkish legislation is carried out by using a four-point scoring chart, and second, the effect of the convention on the judicial decisions was examined by considering whether the Bern Convention was clearly referred in the relevant judicial decisions-47 Council of State decisions were analyzed from 1984 to 2019. It is observed an improvement in Turkish wildlife legislation increased from 17 to 74% per the Bern Convention's goals and objectives. The proportion of judicial decisions referred to the Bern Convention, which resulted in a positive ecological decision was 87.5%. Decisions that do not refer to the Bern Convention were 66% positive. A comprehensive evaluation of both judicial decisions and legislative analysis showed that there are many deficiencies, especially in terms of migratory species and interstate coordination. To improve judicial decisions, courts should be subjected to mandated capacity-building training/workshops concerning international conventions.