The aim of this follow-up study, based on individual data, was to analyse the influence of ethnicity and other demographic and social factors on suicide rates between 1986 and 1989 for the Swedish population according to the 1985 census. The data were analysed by sex and age using a Poisson regression model. During the study period there were 8,310 cases of suicide and undetermined death. The main finding in this study was that ethnicity, defined as being foreign-born, was a significant risk factor for suicide in both sexes and in all age groups except for males aged 30 to 49 years. Not being married was a significant risk factor in all age groups for both males and females. Form of tenure, i.e. living in rented flats, was a significant risk factor for suicide in middle-aged males and females, while over-crowding was a risk factor for middle-aged males and for the over 50's of both sexes. As ethnicity, defined as foreign-born, was an important variable related to suicide, the association between different ethnic groups and suicide will be evaluated in forthcoming studies.