I describe behavior with impact on health in adolescents against the background of characteristics of the Swedish society and analyse possible areas for improvement. A total of 4500 adolescents, aged 13-18 yr, in seven areas answered an anonymous questionnaire. Their socioeconomic backgrounds reflected mainstream adolescents. The response rate was 80-85%. Questions concerned health habits, exploratory behaviors regarding sexuality, use of alcohol and tobacco, problem behaviors, such as getting drunk, and life quality. There was very little experimentation with regard to health habits learned in childhood. Rapid adaptation to adult life-styles occurred, which was similar in both sexes in the younger age groups, but there were significant differences among older students. Alcohol use is of considerable concern. Adolescent prediction of future behavior indicated that negative behaviors require intervention. Parental influence on adolescent behavior needs to be explored. Peer groups could be an additional area for intervention.