Although atherosclerosis is the leading cause of death in the so-called affluent societies, there is presently no drug in our pharmacologic armamentarium against disease to either prevent or reverse this insidious killer and debilitant of human lives. Because of this void the First Brook Lodge Symposium on Anti Atherosclerosis Drug Discovery was convened at Brook Lodge in Augusta, Michigan, August 13-15, 1975. The symposium was sponsored by The Upjohn Company and was international in scope, with investi gators attending from such countries as England, Japan, Belgium, and Italy. The symposium focused on the problems associated with the discovery and evaluation of new drugs effective in preventing or reversing atherosclerosis. The thrust of material is centered around animal models useful as tools in the search and evaluation of new drugs. Broadly categorized, the models are nonhuman primates, rabbits, rodents, quail, and tissue culture. The material is a mix of studies on serum lipids and, more importantly, of studies on the artery, irrespective of serum lipid levels. The prevention of arterial lesions, not reduction of serum lipids, is emphasized. A review of all anti-atherosclerotic agents, with the exception of hypolipidemic agents, is included in this volume of the proceedings of the symposium.