The aim of the study was to explore the prevalence of different smoking habits in a population of Austrian pupils, 12 to 15 years old, and the relationship of familial and peer group smoking customs with these habits. In 1997 a population-based survey (International Study of Asthma and Allergies in Childhood, ISAAC) was conducted of all 7th and 8th grade school children of a district of Upper Austria. Information on the smoking habits of the adolescents, the family members, and of the peer as well as smoking habits of the teacher, gender, and age of the children was collected. The overall-prevalence of having ever smoked in this population is 57.8%. The percentage of eversmokers among the 12-year-olds is 50%. This amount increases to 63.8% among the 14- to 15-year-olds. The odds ratios for smoking daily is highest among those whose best friend smokes (OR: 70.63, CI: 9.19, 542.40). The risk of daily smoking increases also if the siblings of the juvenile (OR: 4.71, CI: 1.15, 19.35) or the mother (OR: 4.95, CI: 1.67, 14.70) smoke. If the father smokes the risk to smoke monthly is increased (OR: 2.09, CI: 1.28, 3.40). These results point to the fact that smoking prevention programes should take into account the influence of peers and family of the adolescents.