Providing adequate water, sanitation and hygiene (WASH) services is critical to improving the survival, health and development of children, women and community at all. In Tanzania, WASH-sensitive indicators such as diarrhoea and stunting are high. Campaigns to encourage simple hygiene practices like washing hands with soap can reduce the incidence of diarrhoea by an estimated 47 per cent while use of proper sanitation can reduce cases of diarrhoea by an estimated 36 per cent. Poor access to WASH has an unaffordable high cost, wasting resources that could be used for furthering the country’s development agenda. It is estimated that Tanzania spends 70 per cent of its health budget on preventable WASH-related diseases as the majority of the population does not have access to improved sanitation, and close to half of the population does not have access to clean drinking water. Without adequate WASH facilities, homes, schools and health centers become breeding grounds for diseases that kill children and threaten their ability to grow. Girls, children with disabilities and children living in rural areas are most affected. This further heightens inequities and uneven opportunities for development. The impact of poor WASH on children living in crisis situations also affects their chances of survival.