In this review we have collected data from epidemiologic studies and clinical trials published from 1968 to 1989 on the relationship between dietary fat and risk of coronary heart disease. Although the reported observational studies of diet and coronary heart disease provide general support for the classic diet-heart hypothesis, evidence of specific dietary lipids is weak. A positive association with saturated fat intake was seen in two prospective studies. A positive association with cholesterol intake was found in only two cohort studies, and an inverse relationship with polyunsaturated fat intake in only one. Clear evidence from dietary trials in the prevention of coronary heart disease has not been found. The analysis of trends in coronary heart disease and stroke mortality of developed countries has shown a discrepancy between fat intakes, cholesterol levels and mortality. The reduction in intake of certain foods "at high risk" such as meat, eggs, milk and cheese, as a preventive intervention, is based on weak scientific evidence. A strategy program has to emphasize the maintenance of ideal body weight by caloric control, an adequate level of physical activity, and the control of other risk factors such as hypertension, hypercholesterolemia, and diabetes.