Ukraine's aspiration for European Union integration has been defined in national policies, laws and international treaties since 1994: within the Partnership and Cooperation Agreement framework between Ukraine and the European Union (1994), the Eastern Partnership (2009), the Law of Ukraine "On the Principles of Internal and Foreign Policy" and many others. However, all these documents were of a predominantly advisory nature, without establishing a strategic need for approximation of Ukrainian legislation to EU norms, especially in the field of environmental protection and climate change mitigation. The Association Agreement between Ukraine and the European Union, signed in 2014, aims to gradually bring Ukrainian legislation in line with objectives enshrined in the EU law, which envisages "transposition" of EU law norms into the Ukrainian legal system. This paper provides detailed assessment of main stages and achievements of Ukraine’s approximation process to the European environmental law (both in terms of Eastern European specifics of environmental regulation and national challenges), and puts emphasis on institutional challenges, environmental and climate governance, proficient translation of European legislation and key requirements for public administration, related to environmental laws’ approximation.