The prevalence of radiologically detectable aortic calcifications, the cross-sectional area of the aortic arch, pulse wave velocity and cardiovascular risk factors were examined in 133 newly diagnosed non-insulin-dependent diabetic patients aged 45-64 years and in 144 randomly selected control subjects of the same age. In addition, the relationship between aortic calcifications and coronary heart disease was examined. Diabetic men tended to have more frequently calcifications in the abdominal aorta than nondiabetic men, whereas such a difference was not found between diabetic and nondiabetic women. No difference was observed between diabetic and nondiabetic subjects in the prevalence of calcifications of the aortic arch. Among cardiovascular risk factors, smoking was associated with calcifications of the abdominal aorta in diabetic and nondiabetic men. Ischemic ECG abnormalities at rest showed a statistically significant association with the presence of abdominal aortic calcifications in diabetic men. The cross-sectional area of the aortic arch increased with age both in diabetic and in nondiabetic subjects and was larger in diabetic than in nondiabetic men. Diabetes did not show any significant effect on pulse wave velocity. An increased frequency of calcifications of the abdominal aorta and a dilatation of the aortic arch in newly diagnosed non-insulin-dependent men as compared with nondiabetic men is compatible with the view that an accelerated development of atherosclerotic lesions of large arteries starts already in an early, asymptomtic phase of this type of diabetes.