The purpose of this investigation was to determine the prevalence and correlates of abnormal urinary albumin excretion and to examine the possible additive effects of cardiovascular risk factors on urinary albumin excretion in African Americans with type 2 diabetes mellitus. One hundred fifty-one African-American subjects who met WHO criteria for type 2 diabetes were included in this cross-sectional analysis. Subjects were identified through computerized medical records from a family medicine clinic and a community health center. Urinary albumin excretion ratios (UAER) were determined from overnight samples. The prevalence of abnormal urinary protein excretion was 51%. Of those with abnormal protein excretion, 36% had microalbuminuria and 15% had macroalbuminuria. Diabetes duration, waist to hip ratio, blood pressure, and total- and LDL cholesterol were significantly higher in subjects with macroalbuminuria. Regression analysis indicated that mean arterial blood pressure, diabetes duration and total cholesterol were independently associated with UAER. Mean UAER significantly increased with the addition of one or more syndrome X risk factors to pure diabetes. Our results indicate that African Americans with type 2 diabetes mellitus have a high prevalence of abnormal urinary protein excretion, which is associated with a clustering of additional cardiovascular risk factors. The fact that this increased risk was associated with hypertension indicates that screening for albuminuria in this population is essential and that a majority of African Americans with diabetes may be at risk for developing cardiovascular complications.