THE RELATIONSHIP between blood levels of cholesterol and coronary artery disease has been a subject of continued interest for the past several years. In October, 1959, a study was begun of the effects of a moderate fat diet (relatively high in polyunsaturated fatty acids) on the blood cholesterol levels and survival of men in the 20- to 50- year age bracket who had had documented myocardial infarctions. This work had been stimulated by that of Jolliffe and associates, who had reported the effect of a similar diet on blood cholesterol levels of high coronary-risk, middle-aged men in New York City, and by Stamler in his report on men prone to coronary disease. A review of the first 12 months of experience with the first 99 subjects on a 30% fat diet had shown that there was no difference in response between one group, who had a polyunsaturated to saturated fatty