UNICEF Innocenti's Report Card 17 explores how the 43 Organisation for Economic Co-operation and Development (OECD) and/or the European Union (EU) countries are faring in providing healthy environments for children. Do children have clean water to drink? Do they have good-quality air to breathe? Are their homes free of lead and mould? How many children live in overcrowded homes? How many have access to green play spaces, safe from road traffic? Data show that a nation's wealth does not guarantee a healthy environment. Far too many children are deprived of a healthy home, irreversibly damaging their current and future well-being. Beyond children's immediate environments, over-consumption in some of the world's richest countries is destroying children's environments globally. This threatens both children worldwide and future generations. To provide all children with safe and healthy environments, governments, policymakers, businesses and all stakeholders are called to act on a set of policy recommendations. The report focuses on the following questions: (1) How do environmental factors affect children's well-being? (2) How are many of the world's richest countries faring in terms of providing a healthy environment in which children can live, develop and thrive? and (3) What actions can these countries take to improve the environments in which children live? [This report was written with contributions from Dominic Richardson, Gunilla Olsson, Celine Little, Dagna Rams, Gro Dehli Villanger, Nicole Quattrini, Tim Huijts, Mirza Balaj and Terje Eikemo.]