Contamination of weaning foods and water with enteropathogenic micro-organisms has been recognised in the past, but its link with the development of diarrhoea by young children in developing countries is lacking. This may explain the unavailability of effective interventions to reduce the risk of diarrhoeal diseases from this contamination. The frequency of contamination of weaning foods with enteropathogens is high in developing countries, and is dependent on the food type, storage time and ambient temperature of storage, the method used, and the temperature reached on re-warming before re-feeding. Other considerations are the bacterial content of cooking and feeding utensils. Fruit and raw vegetables can become contaminated with enteropathogenic micro-organisms by sewage-containing irrigation water, by washing produce and fruits in contaminated water, and how they are processed at home. In most studies reviewed, the level of contamination is higher in weaning foods than in drinking water. Since there is a need to reach a critical level of contamination before illness can occur after the ingestion of an enteropathogen, it is postulated that weaning foods are probably more important than drinking water for transmission of diarrhoeal diseases in developing countries. Several potential interventions have been identified, which should be developed and tested in controlled trials in developing countries. These interventions are needed to reduce contamination of weaning foods in households from developing countries, while adequate facilities for the provision of clean water and sanitation to those communities are placed.