Despite a significant decrease in mortality from cardiovascular disease in the US over the past decade, coronary artery disease, more specifically myocardial infarction, remains the leading cause of death in our country, and in most Westernized countries of the world. The disease process of atherosclerosis causes coronary heart disease; yet, despite considerable progress, much remains to be learned about the basic mechanisms responsible for this disease process. It is the purpose of this paper to review the recent advances that are contributing to our understanding of the important role of plasma lipoproteins in atherosclerosis and the role of dietary fat and cholesterol in altering plasma lipoprotein metabolism.