Combined dyslipidemia is the concurrent presence of multiple abnormalities in various lipid subfractions, including elevated concentrations of low-density lipoprotein (LDL) cholesterol and triglycerides (TGs), as well as decreased concentrations of high-density lipoprotein (HDL) cholesterol. The Adult Treatment Panel III (ATP III) guidelines of the US National Cholesterol Education Program (NCEP) lowered the cut points for classification of TG levels, established non-HDL cholesterol levels as a secondary target of therapy in patients with TGs of >or=2.26 mmol/L (200 mg/dL), and defined the metabolic syndrome as a secondary target of therapy. Although 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) are first-line therapy for most patients with elevated LDL cholesterol, statin monotherapy may not be sufficient to achieve recommended non-HDL cholesterol goals, and statins have only modest effects on reducing TG levels. Similarly, patients whose TG levels remain elevated despite treatment with a TG-lowering agent may require the addition of a statin to provide further TG reduction. In addition, statin therapy may be needed to offset the secondary increase in levels of LDL cholesterol that frequently results from treatment with a TG-lowering agent in patients with marked hypertriglyceridemia. In a number of small studies, the combination of statins and omega-3 fatty acids has been consistently shown to be an effective, safe, and well-tolerated treatment for combined dyslipidemia. Patients with recent myocardial infarction may also benefit from this combination. When considering risks and benefits of adding a second agent to statins for treatment of combined dyslipidemia, omega-3 fatty acids provide additional lipid improvements without requiring additional laboratory tests and do not increase risk for adverse muscle or liver effects.