Early childhood caries is a severe form of dental decay that affects infants and toddlers. It is a chronic, multi-factorial, infectious disease. It should be considered as a symptom of paediatric disorders and lack of adequate care. The caries is particularly virulent, it develops rapidly, often soon after teeth erupt and it begins on tooth surfaces which are usually only affected to minor extent. The condition is particularly frequent in various minority (racial, cultural or ethnic) communities, single parent or low-income families etc. The manifestations include pain, infection, abscesses and chewing difficulties that affect a child's ability to eat and sleep. It thus has debilitating effect on the development, speech general health and self-esteem of infants. The problem should be addressed rather from the paediatric than dental point of view and the appearance of a single carious lesion an any tooth surface during the first 3 years of life must be considered a serious health problem. Early childhood caries is a preventable disease, that can be addressed by targeted preventive measures and professional health invention (provided by dentists as well as paediatricians), and by targeted community preventive programs.