Introduction: Alcohol consumption and drug use, as well as alcohol- and drug-related problems, vary considerably in different regions in Sweden, and between men and women of different ages. Aim: The aim of the present study was to examine the regional, gender and socioeconomic distribution of risk consumption of alcohol, alcohol dependency and drug use in a random sample in Sweden. Material and methods: In both May 2003 and 2004, 7200 gender-stratified adults (a total of 14,400), randomly selected from 12 regions in Sweden, were contacted by mail, and asked to fill out an enclosed questionnaire. The questionnaire concerned use of alcohol, alcohol-related problems, and use of illicit drugs. Results: Heavy alcohol consumption and cannabis use were more frequent in the south of Sweden than in the north, and the further north, the lower the frequency. Alcohol and drug use decreased with age, and was higher for men than for women. On average, 11.5% of all men and 5.0% of all women consumed alcohol intensively at least weekly, 8.6% of men and 4.5% of women had a generally high alcohol consumption, 4.1% of men and 2.5% of women were alcohol addicted, and 2.9% of men and 1.3% of women had used cannabis during the last 12 months. Conclusions: High alcohol consumption and use of illegal drugs seem to be more prevalent in those parts of Sweden that are closer to the European continent. In our opinion, this might be an effect of the closeness to other European countries with lower prices for alcohol, less strict alcohol control policies, and higher availability of drugs. Consideration of regional, gender and age differences in problems related to alcohol and drugs seem to be important in the planning and development of preventive activities.