Lipids play a key role in the progression of atherosclerosis, and lipid-lowering therapies have been studied for 30 years in coronary disease. Measurement of the progression of atherosclerosis through carotid intima-media thickness, coronary mean lumen diameter, and, mostly recently, intravascular ultrasound is generally accepted. This article reviews the role of lipid-lowering therapies in changing the rate of atherosclerosis progression in the coronary and carotid circulations. Statins are the primary therapy used to reduce atherosclerosis and cardiovascular events, including strokes and transient ischemic attacks, and have benefits in reducing events in patients undergoing carotid endarterectomy. In contrast, data for other agents, including fibrates and nicotinic acid, in reducing the progression of atherosclerosis are less extensive and not as well known. There is increasing interest in optimizing the whole lipid profile, as this might deliver extra benefits over and above statin therapy alone. Initial proof of this concept has recently come from studies that measured the progression of atherosclerosis and showed that adding nicotinic acid to statin therapy and, more directly, infusion of high-density lipoprotein-like particles reduced progression and indeed might induce regression of the disease. It is likely that the management of significant carotid stenosis will become ever more drug focused and will be customized to the lipid profile of each patient with intervention reserved only for late-stage symptomatic disease.