OBJECTIVE: To compare glycemic control of black and white patients under treatment for non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: Medical records of patients with NIDDM were reviewed at 19 of 24 clinics or health centers in a specified area of north central Florida. Data were abstracted from the charts of all non-Hispanic black (n = 248) or white (n = 280) patients who met preset eligibility criteria. RESULTS: The mean ± SD age was 58 ± 14 years; the mean ± SD duration of diabetes was 9 ± 7.5 years. Of 528 patients, 220 were treated with oral hypoglycemic agents, 269 were treated with insulin, 28 were treated with diet alone, and 11 were treated with a combination of oral agents, diet, and insulin. Glycosylated hemoglobin was ≥8% for 47% of black women, 41% of black men, 38% of white men, and 29% of white women. The less favorable control status of the black women persisted within categories of age (40–59 years or ≥60 years), treatment (insulin or oral hypoglycemic agents), time since diagnosis (less than versus greater than or equal to the median of 7 years), and obesity (noted versus not noted in chart). In multiple logistic regression analyses controlling simultaneously for these variables, the odds (95% confidence interval [CI]), compared with white women, of having glycosylated hemoglobin ≥8% were 2.2 (1.4, 3.4) for black women and 1.5 (0.8, 2.9) and 1.4 (0.8, 2.5) for black and white men, respectively. CONCLUSIONS: Black women were more likely than white women or men to have glycosylated hemoglobin ≥8%. This difference was not readily explained by age, type of treatment, time since diagnosis, or a notation of obesity in the medical record, although an effect of obesity cannot be excluded on this basis.