Several lipid parameters were evaluated in 88 patients with acute myocardial infarction (AMI). A reduction in cholesterol and phospholipid level was observed, with minimal values between the days 10-20, followed by a subsequent increase. Triglycerides increased after 12-14 hours, with a maximal value after 20-30 days. Cholesterol bound to high-density lipoproteins (HDL-cholesterol) decreased after 24 hours, with a minimal value after 20-30 days. Apoprotein A decreased from the initial measurement until days 20-30. The initial lipid profile (indicating the risk of coronary artery disease) was constituted by high cholesterol (particularly in males below 60 years), high triglyceride and low HDL-cholesterol levels. The latter finding was more marked and characteristic in the overall group of evaluated patients. All values were compared with a control group of 24 healthy persons. Relevant data for prognosis included the following: males above 60 years had a greater reduction in cholesterol and apoprotein A during AMI; the males who died had lower apoprotein A levels than the survivors; females with higher haptoglobin levels also had higher apoprotein B levels. All these findings were statistically significant (p less than 0.01).