Asthma is the most common chronic illness in childhood and is characterized by variable airflow obstruction with airway hyperresponsiveness. In the United States, asthma affects an estimated 14-15 million persons, including 4.8 million (6.9%) aged < 18 years. In 1993, asthma accounted for an estimated 198,000 hospitalizations and 342 deaths among persons aged < 25 years. To characterize national trends in mortality and hospitalizations attributable to asthma among children and young adults (persons aged < 25 years) during 1980-1993, CDC analyzed mortality data from its multiple cause-of-death files and hospitalization data from the National Hospital Discharge Survey. This report summarizes the results of that analysis, which indicate that asthma-related mortality and hospitalization rates are increasing among persons aged < 25 years.