Nature is a silent victim of the armed conflict between the Russian Federation and Ukraine, which began in 2014 as a proxy war, led to the occupation of parts of Ukrainian territory and in 2022 escalated into a full-scale war unseen in Europe since 1945, with attacks in the vicinity of nuclear objects, natural reserves becoming battlegrounds, air, land, and water becoming contaminated with debris and chemical substances, and with animal species being decimated. At the same time, Ukraine is one of the few nations in the world to have criminalised ecocide as a crime distinct from other crimes against nature. This chapter will address the investigations of ecocide in the context of the armed conflict in Ukraine. It will open with an overview of the environmental damage caused by the conflict resulting from the Russian aggression against Ukraine and will proceed with the description and analysis of the Ukrainian legislation on ecocide. It will then address the investigations of ecocide run by Ukraine and explain the challenges encountered by the Ukrainian authorities in the investigation of environmental damage resulting from armed conflict. Finally, the chapter will attempt to demonstrate how this experience may be beneficial for the international efforts to criminalise ecocide.