Investigations on diet, body weight, and lipoproteins were carried out in 28 patients with stable angina pectoris. They consumed a linoleic acid-enriched diet (P/S ratio = 2) for a period of 2 years. The total fat content remained constant before and during intervention, contributing 34% to energy intake. During intervention serum total cholesterol and the total/HDL cholesterol ratio decreased significantly, but HDL cholesterol did not change. Changes in body weight were significantly inversely related to changes in HDL cholesterol and positively to the total/HDL cholesterol ratio. Changes in alcohol intake were significantly positively related to both total and HDL cholesterol but unrelated to the total/HDL cholesterol ratio. From the results of this long-term study it can be concluded that a moderate fat diet with a P/S ratio of 2 can lower total cholesterol effectively without affecting HDL cholesterol.