Abstract ? Denmark, Iceland, Norway, and Sweden have all had a similar decline in dental caries during the last 20 years, although the decline has come later in Iceland. The purpose of this study was to compare the caries-preventive methods used for children and adolescents in these four countries. Questionnaires were sent to random samples of dentists, dental hygienists, and dental nurses working with children during 1995 and 1996. The results showed that the use of preventive methods was generally consistent between the countries. Nevertheless there were differences between the countries concerning the choice of preventive strategy for risk patients and also in how prevention was implemented. Danish dental care providers chose oral hygiene education as the priority, which they put into practice. Apart from fluoride varnish for some patients, most of them did not use or recommend fluoride except fluoride toothpaste. The Norwegian and Icelandic dental care providers chose both oral hygiene education and the use of fluoride as priorities, while most Swedish dental care providers preferred to provide dietary advice and oral hygiene education, and additional fluoride for risk patients. The differences could not be explained by other variables than nationality, implying that there are differences between the dental cultures in the four countries. The informational basis of decisions on preventive strategies varied between the different dental professionals in each country as well as between the countries, indicating that national professional cultures are being shaped differently. Despite the differences in choice of preventive methods, the dental health of children varies little across the frontiers. This raises the question of the significance of the choice of preventive methods to the decline of dental caries and points towards an urgent need to develop evidence-based preventive strategies.