Despite a remarkable reduction in prevalence of dental caries in the developed countries, childhood tooth decay is still a public health problem, and it is well known that children from disadvantaged communities and from minority ethnic groups continue to experience a high level of disease. Even in Sweden there are groups of children in need of early intervention to prevent oral diseases, and especially socially deprived city communities require special attention. Here, preventive strategies adapted to children and families with a multicultural background are needed. The aim of this study was to evaluate a comprehensive oral health programme, based on a High-risk group strategy, and directed towards young children living in a low socio-economic, multicultural area in the city of Malmö, Sweden. The specific aims were to investigate the effect on the prevalence of dental caries after one and three years of intervention, and the impact of parent education and training on various factors related to caries development. 804 2-year-old children were enrolled in the programme and constituted the Intervention group. These children were recalled every 3rd month between ages 2 and 3 years and semi-annually between ages 3 and 5 years for individualized oral health information. Except for the yearly dental examinations the information took place at an outreach facility located in the local shopping area, not in direct connection with the local Public Dental Service clinic. The parent information focused on tooth-brushing and dietary habits, and fluoride tablets were provided free of charge. Clinical examinations were carried out at baseline (2 years of age) and at age 3 and 5 years. On the same occasions the guardians were interviewed with the aid of a structured questionnaire. The results after one year of intervention (3 years of age) were compared with a non-intervention Reference group from the same district consisting of 217 children of the same age. A final comparison between the groups was made at the age of 5, after three years of intervention. The programme significantly reduced the caries increment during the 3 year period of study. The main impact of the programme was noted during the first year of study, the number of caries-free children at the age of 3 (initial and cavitated lesions included) being 37% in the Intervention group as compared with 15% in the Reference group (p<0.001). At the age of 5, the corresponding figures were CV 14% and 6% (p<0.001). At this age, 45% of the children in the Intervention group had cavitated or filled lesions compared with 67% in the Reference group (p<0.001). The self-reported compliance with taking fluoride tables was high in the Intervention group and the difference between the groups was considerable. No difference in the reported use of fluoride toothpaste was found, the use being close to 100% in both groups. A significant positive effect on the dietary habits, recorded as frequent small-eating and sweet drinks at night, was seen after one year of intervention, but no significant difference between the two groups was found after 3 years. The programme had a positive effect on the parents’ brushing habits, but no effect on the oral hygiene level. In conclusion, the study showed that the oral health programme, using conventional caries-preventive measures, significantly improved the oral health situation in this multicultural, low socioeconomic city area of Malmö. The main caries preventive impact was noted during the first year of study, which was haracterized by a more intense preventive intervention. A high compliance with the programme might be explained by the use of an outreach facility for oral health information, located in the centre of the local community.