The aim of this study was to identify the predisposing and enabling factors affecting mothers' hygiene behaviour in relation to childhood diarrhoeal diseases. Qualitative data were gathered by naturalistic observation of 12 mothers and focus group discussions involving 32 mothers. Mothers with children less than 2 years of age in both urban and rural areas of Suphanburi, a central province of Thailand, were sampled. Twelve local terms describing five different types of diarrhoea were identified. Childhood diarrhoea was classified into two groups depending upon perceived causes: contagious and preventable, and not contagious and unpreventable. To prevent diarrhoea in children, mothers reported that they avoid "taboo" food, avoid breastfeeding with "hot" milk and visit local healers for a herbal paste treatment that is applied to the child's throat. Most mothers did not wash their hands before preparing milk or after disposal of children's faeces. However, they did wash their hands after cleaning the child following the child's defecation, and after their own defecation. Our findings suggest that health education programmes should utilize local terminology and work to counter common misunderstandings regarding childhood diarrhoeal disease and its prevention. Knowledge of the predisposing and enabling factors identified in this study will assist in the development of effective implementation programmes.