OBJECTIVES: Preventable hospitalizations are a good indicator for assessing the quality of health services in the community. A previous study reported that the burden resulting from avoidable hospitalizations due to short-term uncontrolled diabetes was substantial. This study is designed to assess the disparity in preventable hospitalizations among blacks. METHODS: The 2004 National Hospital Discharge Survey was analyzed. This nationally representative survey is conducted annually under the auspice of the Centers for Disease Control and Prevention. Hospitals with an average length of stay fewer than 30 days, hospitals with general specialization (surgical and medical), and children's general hospitals were included. Institutional hospitals such as Federal, military, and Department of Veterans' Affairs hospitals, and hospitals with less than six beds staffed for patient use were not included in the sampling frame. Overall, the hospital response rate was 92%. RESULTS: Among 5.2 million hospitalizations with diabetic conditions, approximately 609,000 hospitalizations were primarily due to diabetes. Among hospitalizations mainly due to diabetes, uncontrolled diabetes conditions accounted for 32% (191,000) of the admissions. Roughly, 97,000 (51%) of hospitalizations were of whites, 41,000 (21%) of blacks, and the remaining 53,000 (28%) were of other races. During the year 2004, per 10,000 populations, blacks had more preventable hospitalization (5 for whites, 11 for blacks, and 9 for others). Per 10,000 people with diagnosed diabetes, whites had 83 preventable hospitalizations and blacks had 176 preventable hospitalizations. CONCLUSION: Hospitalizations in an acute and potentially life threatening condition due to short-term uncontrolled diabetes is relatively common among blacks. This result reflects inadequate primary health care among black people with diagnosed diabetes. Improved primary health care and diabetes care education among black population would narrow the disparity of preventable hospitalizations.