OBJECTIVES To examine the association of race/ethnicity with medication use, emergency hospital care (EHC) utilization, and quality-of-life outcomes in a population with persistent asthma and to determine if factors related to severity of illness, treatment characteristics, and demographic, socioeconomic, and smoking status explain differences in study outcomes. STUDY DESIGN Retrospective analysis. METHODS We examined survey and administrative data for 974 adults with persistent asthma enrolled in a group-model health maintenance organization. Patients with persistent asthma were identified in 1999 using Healthcare Effectiveness Data and Information Set inclusion criteria. In 2000, the same patients were surveyed regarding quality of life using the Mini Asthma Quality of Life Questionnaire. In 2001, the use of controller medications, the ratio of controller medications to rescue medications, and EHC utilization were identified by electronic medical record. Multiple logistic regression and linear regression analyses were used to evaluate the independent association of race/ethnicity with study outcomes after adjusting for severity of illness, treatment characteristics, and demographic, socioeconomic, and smoking status. RESULTS Compared with whites, African Americans (standardized β coefficient, -0.12) and Native Americans/Aleutians/Eskimos (standardized β coefficient, -0.14) had lower Mini Asthma Quality of Life Questionnaire scores (P <.05 for both). African Americans were significantly (P <.05) more likely to report EHC utilization (odds ratio, 5.2; 95% confidence interval, 2.6-10.3). CONCLUSIONS Disparities existed in 2 outcome measures, Mini Asthma Quality of Life Questionnaire scores and EHC utilization. A concerning finding is that African Americans were at least 5 times more likely to report higher EHC utilization, even after adjusting for factors such as income and education.