To determine if patterns of predominant asthma disease activity are more closely related than baseline asthma severity to measures of morbidity (acute asthma attack, emergency room visit/hospitalization, missed school days, and/or steroid burst). Retrospective analysis was performed for inner-city Los Angeles asthmatic children (3 to 18 years of age) during their first year of enrollment in an asthma-specific disease management program. All measures of morbidity were more closely related to patterns of predominant disease activity than baseline severity. We conclude that patterns of predominant disease activity are a more significant predictor of asthma morbidity than is baseline severity.