The occurrence of diabetic ketoacidosis (DKA), a serious but largely preventable acute complication of diabetes mellitus, has been declining in recent years. However, empiric observations indicate that DKA continues to have a major effect on ethnic minority patients in inner-city settings. In this study, we conducted a retrospective analysis of five-year hospital admission data for DKA at a single inner-city hospital that serves a largely uninsured adult African American population. A computer-assisted search of the International Classification of Diseases, Ninth Revision, Clinical Modification codes for DKA revealed 847 admissions for confirmed DKA in 630 patients. Of these, 592 (94%) were African Americans, 22 (3.5%) were Whites, and 16 (2.5%) were Hispanics. The mean age was 43.4 +/- .4 years. Five hundred seventy-one (90.6%) of the patients had type 1 diabetes, and 59 (9.4%) had type 2 diabetes. One hundred forty-five patients (23%) were newly diagnosed with diabetes. Ninety-four (14.9%) of the patients had multiple admissions, ranging from 2 to 23 admissions per patient during the five-year period, while the remaining 391 (62.1%) patients were single admissions. Half of the patients (52%) did not have health insurance. Major precipitating factors for DKA included discontinuation of insulin, infection, and other medical illness in 501 (59.1%), 136 (16.1%), and 30 (3.5%) of the admissions, respectively. In conclusion, these data demonstrate that DKA continues to have a major effect in urban African American patients with diabetes. Therefore, multiple targeted interventions are needed in this population to improve diabetes care and thereby decrease the frequency of DKA.