Recent studies suggest that psychosocial factors may contribute to asthma. We examined associations of stressful life events with asthma prevalence and morbidity among Chicago adolescents. Self-reported asthma, measures of asthma morbidity, and 15 life events were collected from 2026 seventh to ninth grade students from 34 Chicago Catholic schools as part of the International Study of Allergies and Asthma in Childhood in 1994-95. Life events were reported by 77% of adolescents and overall asthma prevalence was 15.5%. Stressful life events in adolescents were significantly related to both asthma and asthma morbidity. Odds of asthma was 1.44 (95% confidence interval [CI] = 1.07, 1.95) for those reporting two to three stressful events and 1.92 (95% CI = 1.41, 2.62) for subjects endorsing more than three stressful events. In adolescents with asthma, number of asthma symptoms (odds ratio [OR] for increase in one event = 1.16, 95% CI = 1.07, 1.27), asthma-related school absenteeism (OR = 1.17, 95% CI = 1.04, 1.32), physician visits for asthma (OR = 1.16, 95% CI = 1.04, 1.29), and hospitalization for asthma (OR = 1.20, 95% CI = 1.001, 1.44) were significantly associated with the number of stressful events, independent of home exposure to cigarette smoke and dampness, use of inhaled substances, and sociodemographic factors. While these results are not sufficient to assign causality in the relationship between stress and asthma, they are supported by a number of other studies and by plausible biologic mechanisms. Assessing and addressing the effects of stressful life events may be helpful in managing asthma in inner city adolescents.