OBJECTIVES: Previous studies suggest an underuse of evidence based drug therapies for chronic disease treatment in for underserved. This study examines utilization patterns for the heart failure drug, BiDil and its generic components, isosorbide dinitrate and hydralazine. BiDil was marketed for African Americans as a primary therapy for congestive heart failure, a particularly prevalent problem in this population. METHODS: The analysis uses a repeated measures ANOVA with data obtained from the Center for Medicaid and Medicare Services for 1999-2008.  Prescriptions were segmented by calendar quarters.  Data were extracted using National Drug Codes for BiDil and for each generic. State level data were combined by United States Census-defined regions. The model determined if there are significant differences in prescription rates controlling for sex, age, race, geographic region, and proportion non-white. RESULTS: Approximately 50% of prescriptions for BiDil were from the 17 state South region with a 20% African American population. The least number of prescriptions (7%) were from the West region comprising 13 states and 10% African Americans.  The Northeast and South regions had the earliest BiDil uptake. Isosorbide rates showed a steady decline from 1999 to 2008 with no significant shift after BiDil’s market introduction in July, 2005. Hydralazine use showed a similar pattern. Early analysis demonstrated a correlation between geographic region and utilization. Additional analyses use National Center for Health Statistics ambulatory care survey data to assess the significance of the regional correlation and the extent to which race and other patient factors influence use of BiDil or its generics.   CONCLUSIONS: Demographic variation suggests differences in prescription rates by racial makeup within regions as expected. Overall utilization of BiDil or its generics is low or declining. Further research is required to investigate the factors influencing use of BiDil as a heart failure therapy.