Pollution is the world’s largest environmental cause of disease and premature death. The Lancet Commission on pollution and health brought together leaders, researchers and practitioners from the fields of pollution management, environmental health and sustainable development to elucidate the full health and economic costs of air, water, chemical and soil pollution worldwide. By analysing existing and emerging data, the Commission reveals that pollution makes a significant and underreported contribution to the global burden of disease, particularly in low- and middle-income countries. The Commission also provides six recommendations to policymakers and other stakeholders looking for efficient, cost-effective and actionable approaches to pollution mitigation and prevention.