To define the prevalence of large vessel disease in Ethiopian diabetic patients, the protocol of the World Health Organisation Multinational Study of Vascular disease in Diabetics was used in the Diabetic Clinic of Yekatit 12 Hospital, Addis Ababa: 221 of the possible 261 patients aged 35 to 54 years were examined during 6 months. One hundred seven were diagnosed diabetic 1 to 6 years before study, 74, 7 to 13 years and 40, 14 years or more before the study. Forty-two percent were taking insulin; 18% had retinopathy, 7% heavy albuminuria. Body mass index (BMI) of less than 18 kg/m2 was found in 13.6%; 6.4% of men had BMI more than 27 and 50% of women more than 25. Only 30 patients had ever smoked cigarettes. The plasma cholesterol was less than 6.72 mmol/l in 90% of the 221 patients. Vascular disease led to the diagnosis of diabetes in 3 patients. At study, 19.9% were hypertensive but only 5% at the time of diagnosis. Only 1 patient had had ischaemic gangrene, 1 a stroke, 4 intermittent claudication, 4 angina pectoris and 1 a myocardial infarction. Electrocardiograms, centrally Minnesota-coded in London, were interpreted as Coronary Disease Probable in only 6 patients, and Coronary Disease Possible in 25; the other 190 tracings were normal. It is concluded that macrovascular disease is uncommon in middle-aged Ethiopian diabetic patients in Addis Ababa.