Three population surveys of asthma, conducted as part of a community-based asthma education program in southwestern Sydney, Australia, illustrate the relationship between health behaviors and asthma morbidity. The first survey was carried out in five secondary schools (n = 2514, 52% participation rate); the second survey, in eight schools (n = 4550, 82% participation rate); and, the third survey was conducted among patients who attended 38 general practices in the region (n = 633 adolescents, 72% participation rate). The prevalence of diagnosed asthma in Australian adolescents across all three studies was 16.5% (95% CI, 15.7%-17.3%). Asthma prevalence declined in males, but increased in females from ages 12-15 years. It was noted that smoking prevalence was similar in asthmatic adolescents, compared with nonasthmatics, and that the adoption of smoking occurred at similar ages. Further, behavioral self-management of asthma was infrequent in this group, with low levels of preventive practice and preventive medication use. We present a conceptual model of the barriers to optimal asthma management among asthmatic adolescents. The results of these surveys have led to community-wide efforts to improve asthma management and decrease smoking prevalence among these adolescents.