In recent years the impact of ever-increasing numbers of refugees on the resources of the host countries has become a global concern. Health personnel face unanticipated demands complicated by different cultural, ethnic and religious factors and an unfamiliar disease panorama. Sweden today has around 1 million immigrants, 15% of the population. The aim of this thesis was to describe oral status with respect to caries and periodontal conditions, to analyse the need for dental treatment, to evaluate the effect of a preventive dental health programme, to study attitudes and knowledge of preventive dentistry and to describe and analyse utilization of dental services by different groups of adult refugees in Sweden. Three different methods were used: a descriptive clinical survey of a random sample of 193 Chilean and 92 Polish refugees, an experimental survey of a random sample of 159 Chilean refugees and a register survey, using national health statistics, consisting of a random sample of 2,489 refugees arriving in Sweden 1975-1985. The Chilean and Polish refugees had markedly poorer oral status than corresponding Swedish population groups. No association could be found between oral health or estimated treatment need and the length of time in Sweden. The simplified preventive program in the form of group discussion had a lasting effect on improved periodontal conditions and also improved knowledge of dental health care in the group of Chilean refugees. The register survey showed a generally low utilization of dental services but a high dental consumption among adult refugees in Sweden. The total treatment time for a course of treatment showed no marked decrease with subsequent courses of treatment. Immigration may have a profound effect on oral health care needs in a given population by introducing undetermined accumulated needs for oral care, and by stimulating changes in attitudes to and preferences in oral health and care.