In 2003, 771 randomly selected two-year-old children from the town of Zurich were examined. Teeth with carious cavities were observed in 12.6% of the children. Caries including initial (not yet cavitated) lesions was seen in 25.3% of children. Caries prevalence was strongly associated with immigrant background. Caries was found in 7.5% of Swiss children and in 38.5% of children from ex-Jugoslavia. 5% of children of mothers born in Switzerland, and 17.4% of children of mothers not born in Switzerland showed caries. The average number of teeth with carious lesions in children with caries was 4.3 irrespective of immigrant or Swiss background. This finding suggests that all kids with caries had similar risk behaviours. Multivariate logistic regressions elucidated the behavioural components associated with caries. The presence of plaque and the use of a night-time bottle proved to be the strongest predictor variables for caries. Frequent drinking of sugared non-milk drinks, age and no pacifier use were further risk indicators in children of foreign-born mothers. A significant improvement of oral health of small children can be achieved by a concerted action of child welfare consultants, paediatricians and carers of day-nurseries. The primary goal is to convince parents to actively participate in preserving dental health of their offsprings. The following recommendations should be adhered to: 1. Parents should brush the teeth of the children daily, using a fluoridated children-toothpaste starting the very day of the appearance of the first milk tooth. 2. At the age of 12 months, the bottle should be replaced by a cup and the continuous use of a nursing bottle while falling asleep and during the night should absolutely be avoided. 3. Children should primarily be offered water and milk as a beverage. A first dental inspection is due at the age of two years.