In the course of a general population survey in Mirano (Venice), Northern Italy, a random sample of 1,903 subjects (50.1% men) aged 20-59 was examined. Fifty-five were diabetic (fasting plasma glucose greater than or equal to 140 mg/dl or diagnosed by a physician) and 1,670 non-diabetic subjects (fasting plasma glucose below 110 mg/dl). In this paper an assessment was made on the more frequent occurrence of coronary risk factors (serum cholesterol and triglycerides, body mass index (BMI), systolic blood pressure, cigarette smoking) and, in particular, of their aggregation in diabetic patients as compared to non-diabetic controls. The occurrence of any one of the coronary risk factors studied was more frequent in diabetic subjects and significantly so for triglyceridemia in both sexes and for systolic blood pressure and BMI in men. The aggregation of two or more risk factors was also more frequent in diabetic subjects than controls. Finally, the combined score of coronary risk as calculated by multiple logistic function showed higher values for diabetic subjects. These results confirm the need for a systematic search for coronary risk factors in diabetic subjects in order to prevent cardiovascular complications.