The purpose of this study was to describe patterns of health care use by inner-city patients with asthma and to identify patients at risk for hospitalization. We performed a retrospective cohort study of 1788 patients with asthma aged 5 to 34 years from a large hospital-based multi-specialty practice in inner-city Indianapolis from 1985 to 1992. Compared with 633 white patients, 1155 African-American patients had fewer outpatient encounters including primary care visits, urgent visits to the emergency department and urgent care centers, and prescription refills. Emergency department use was greater for African-American males compared with white males. With patients 30 years of age as the referent, survival analysis revealed three to sixfold greater relative risk of hospitalization for asthma for younger patient age groups, and greatest risk among young African-American males. Adolescent patients had the highest cumulative percentage hospitalization and the longest lengths of stay. We conclude that inadequate routine primary care among African-American patients may increase their risk of asthma exacerbation requiring hospitalization. Age, gender, and race are all important predictors of hospitalization for asthma. Further studies are needed to explore the relation between sources of care and asthma exacerbation.