Climate change, conflict and human displacement are all growing in scale, increasing the spread of mosquito-borne diseases. A number of effective water, sanitation and waste management measures exist and can be implemented to prevent mosquito-borne diseases. This WHO/UNICEF technical note provides practical information for implementing such measures with a focus on emergency contexts. The intended users of this note are water, sanitation and hygiene (WASH) health partners and practitioners, national and local public health authorities and humanitarian and community-based organizations.