Background: Russia's invasion of Ukraine in February 2022 ignited the largest armed conflict in Europe since World War II. Ukrainian government agencies, civil society organizations, and international agencies have gathered an unprecedented amount of data about the impact of war on the environment, which is often the silent victim of war. We review these data and highlight the limitations of international governance for protection of the environment during time of war., Methods: We performed an integrative review of academic, institutional, and media information resources using the search terms "Ukraine", "Russia", "war", "environment", "health", "human rights", "international humanitarian law", "international human rights law", "ecocide", and "war crimes"., Main Text: Nearly 500,000 military personnel have been killed or wounded during the war, and more than 30,000 civilians have been killed or injured. Indirect health effects of the war have likely accounted for an even greater amount of civilian morbidity and mortality. The war has displaced more than 11 million people. Russia's military forces have caused extensive damage to civilian infrastructure. The war has devastated Ukraine's economy and reduced food and energy security in many countries. The war has caused more than $56.4 billion in damage to the environment. There has been widespread chemical contamination of air, water, and soil, and 30% of Ukraine has been contaminated with landmines and unexploded ordnance. Landscape destruction, shelling, wildfires, deforestation, and pollution have adversely affected 30% of Ukraine's protected areas. Russia's seizure of the Zaporizhzhia Nuclear Power Plant and destruction of the Nova Kakhovka Dam have posed risks of long-term environmental catastrophe. Most of these environmental impacts threaten human health., Conclusion: In addition to enormous human costs, Russia's war on Ukraine has had devastating impacts on the natural environment and the built environment. International law mandates that methods of warfare must be implemented with due regard to the protection and preservation of the natural environment. A just and lasting peace necessitates, among other requirements, rebuilding and restoration of Ukraine's natural environment and built environment. The environmental consequences of all wars need to be investigated and more effective measures need to be implemented to protect the environment during war., (© 2023. The Author(s).)