Diarrhoeal diseases are still a major challenge in Nepal because of inadequate safe water supply, poor sanitation and living conditions. However, several other factors such as the literacy rate, socio-economic status, and social, religious or personal perception of the cause of disease may influence the rate of morbidity and mortality of diarrhoeal diseases. A yearly minimum death of 30,000 and morbidity of 3.3 episodes per child was estimated due to diarrhoea. An environmental health education programme, along with water supply and sanitation intervention, is an effective mitigation measure to reduce diarrhoeal diseases in Nepal.