The report summarizes the estimates of the burden of disease attributable to unsafe drinking water, sanitation, and hygiene for the year 2019 for four health outcomes - diarrhoea, acute respiratory infections, soil-transmitted helminthiases, and undernutrition - which are included in the reporting of the Sustainable Development Goal indicator 3.9.2. The report includes estimates at global, regional and country level for 183 WHO Member States.