Objective: To evaluate the effects of prescription omega-3-acid ethyl esters on non-high-density lipoprotein cholesterol (HDL-C) levels in atorvastatin-treated patients with elevated non-HDL-C and triglyceride levels. Results: Prescription omega-3-acid ethyl esters plus atorvastatin, 10, 20, and 40 mg/d, reduced median non-HDL-C levels by 40.2% vs 33.7% (P<.001), 46.9% vs 39.0% (P<.001), and 50.4% vs 46.3% (P<.001) compared with placebo plus the same doses of atorvastatin at the end of 8, 12, and 16 weeks, respectively. Prescription omega-3-acid ethyl esters plus atorvastatin also reduced median total cholesterol, triglyceride, and very low-density lipoprotein cholesterol levels and increased HDL-C levels to a significantly greater extent than placebo plus atorvastatin. Percent changes from baseline low-density lipoprotein-cholesterol, apolipoprotein A-I, and apolipoprotein B levels were not significantly different between groups at the end of the study.cOnclusiOn: Prescription omega-3-acid ethyl esters plus atorvastatin produced significant improvements in non-HDL-C and other lipid parameters in patients with elevated non-HDL-C and triglyceride levels.Mayo Clin Proc. 2010;85(2):122-128 ANOVA = analysis of variance; apo = apolipoprotein; CHD = coronary heart disease; HDL-C = high-density lipoprotein cholesterol; LDL-C = low-density lipoprotein cholesterol; P-OM3 = prescription omega-3-acid ethyl esters; TC = total cholesterol; VLDL = very low-density lipoprotein; VLDL-C = VLDL-cholesterol