In Norway, prophylactic child health care is organized through local mother and child clinics, each of which serves a given population. This study summarizes the findings from the routine check-up of four-year-olds in a district with a high proportion of immigrant families. The sample consisted of 70 children, 33 of them from immigrant families. The ordinary check-up was supplemented by information obtained by means of a questionnaire, which was filled in by the public health nurse and the doctor in consultation with the parents. A validated scale, or checklist (BCL), for ordinary behavioural problems among pre-school children was also included. The findings must be interpreted with caution, one reason being the large socio-economic differences between the immigrant and the Norwegian families included in the study. Nevertheless, the difference between the eating habits of the two groups of children was striking, in spite of the emphasis placed on diet at the clinic. Another important finding was the poor knowledge of Norwegian among the immigrant children, which was obviously associated with the poor language skills of the mothers. Therefore, an important element of the preventive health work among immigrant children should be to encourage the mothers to attend courses in Norwegian.