Large-scale intervention trials demonstrate that treatment with statins, the most effective lipid lowering drug class, significantly reduces the risk of coronary heart disease events. Recent evidence suggests that more aggressive LDL cholesterol lowering with newly developed statins may provide greater clinical benefit, even in individuals with moderately elevated serum cholesterol levels. There is increasing evidence that statins exert a myriad of other beneficial pleiotropic effects on the vascular wall, thus altering the course of atherosclerotic disease. In the long-term treatment, nonlife- threatening side effects may occur in up to 15% of patients receiving one statin. Significant elevations in the activity of serum aminotransferase and creatine kinase alone or in combination with muscle pain in statin-treated patients should be taken seriously. The combination of the statins with gemfibrozil results in higher rates of drug toxicity. Reports show possible adverse effects of statins on nervous system function including mood alterations, however, statins have also been associated with improvement in central nervous system disorders. Special attention must be paid to the tolerability of the statins in children, elderly and transplant patients. Future clinical studies and surveillance information will warrant long term safety of each member of this class of lipid-lowering agents. New classes of patients with diabetes, metabolic syndrome and renal diseases may have clinical benefits from statins. New upcoming clinical trials will address the fundamental question of whether statin treatment can protect from the natural history of atherosclerotic-related diseases. This will require a more prolonged follow-up (i.e., 10 to 15 years). Finally, the basic understanding of newer pathogenic mechanisms involving the effects of statins on angiogenesis and the nitric oxide pathway should be explored in the clinical setting as well as the study of pathogenic mechanisms by which statins can affect plaque instability.