In addition to standard survey technics, a new procedure for aspiration of depot fat, the determination of urinary vanil mandelic acid, and radioelectrocardiography were utilized for the first time, to our knowledge, under field conditions to study the “metabolic epidemiology” of coronary heart disease. The study sample consisted of 280 men, aged 45 and over (mean, 62), most of whom were randomly selected from five geographic areas in which indigenous diet patterns of the populace could be distinguished. A 12-lead electrocardiographic survey of all subjects revealed 2 cases of residual myocardial infarction. The use of exercise radioelectrocardiography detected 2 cases of definite myocardial ischemia in which the standard electrocardiograms were normal. Thirty-one cases of cardiac arrhythmias were found, the vast majority considered to be due to arteriosclerotic heart disease. The nutritional status of the male Cretan was assessed by interview technics, 24 hour diet recall, clinical examination, hemoglobin, hematocrit and the determination of serum vitamin A and E. The mean level of hemoglobin was 14.1 gm.%; of hematocrit, 43.1%; serum vitamins E and A, 0.97 mg.% (range 0.32–1.8) and 92 μg.% (range 43–168), respectively. Two instances of petechial hemorrhages believed to be due to deficiency of ascorbic acid were found. Two other subjects had serum vitamin E levels below 0.5 mg.%; 8 cases of anemia were detected. With the exception of the cases cited, the mean serum vitamin and hemoglobin determinations were within normal limits; mean hematocrit levels were slightly below normal. Analysis of 200 depot fat samples revealed significant differences which could be associated with specific local dietary patterns. Oleic acid comprised 65 per cent of total depot fatty acids in subjects consuming the greatest quantity of olive oil. The Iracleion subjects ate the most meat and cheese, exhibited the highest mean weight, and showed the highest depot total saturated fatty acid content. When the depot fat composition pattern of all the Cretan subjects was compared to that of American men of the same age, a highly significant difference in depot saturated and monounsaturated fatty acids was revealed. The monounsaturated depot fatty acid content was 69 compared to 59 per cent in the American. Depot saturated fat was 19 per cent in the Cretan, 30 in the American. It was suggested that the populations having low incidence of coronary heart disease may be associated with relatively low depot saturated fat content and a proportionate increase in either depot monoenes or polyenes. In the subsample of 12 subjects a mean level of 24 hour urinary vanil mandelic acid was found to be 6.3 mg.%, an amount found in American subjects with evidence of coronary heart disease. It was postulated that though the urinary vanil mandelic acid excretion of Cretan men is high, reaction to stress is decisive and disassociated with anxiety-provoking behavioral patterns which characterize the coronary-prone subject. In determining the status of our study subjects relative to the risk factors defined by the Framingham study, the rural Cretan man can be said to be hypo- or normocholesteremic, normotensive and normal in weight. He eats little saturated fat, smokes moderately if at all, exercises considerably and tends to react to stress decisively. Thus, all factors of risk studied were found to be of low order, and this combination of findings appears to best explain the low incidence of coronary heart disease observed in the Cretan men.