Background: Effects of omega-3 fatty acids (n - 3 FA) combined with fenofibrate are not yet investigated, compared with fenofibrate. Methods: This was a randomized, single-blind, placebo-controlled, parallel study. Age, sex, and body mass index were matched among groups. All patients were recommended to maintain a low fat diet. Fifty patients with hypertriglyceridemia in each group were given placebo, n - 3 FA 2 g + fenofibrate 160 mg (combination), or fenofibrate 160 mg, respectively daily for 2 months. Results: Placebo, combination, and fenofibrate significantly decreased triglycerides by 7%, 41% and 30%, respectively and triglycerides/HDL cholesterol ratio by 11%, 45% and 32%, respectively relative to baseline measurements (all P < 0.05 by paired t-test). When compared with placebo and fenofibrate, these with combination were significant (P < 0.001 by ANOVA). When compared with placebo, both combination and fenofibrate significantly decreased apolipoprotein B and non-HDL cholesterol and improved flow-mediated dilation and reduced CRP and fibrinogen (all P < 0.05 by ANOVA), however, there were no significant differences between combination and fenofibrate. When compared with placebo, both combination and fenofibrate significantly reduced insulin and glucose (both P < 0.05 by ANOVA), and improved insulin sensitivity (P = 0.005 by ANOVA). However, there were no significant differences between combination and fenofibrate. Conclusions: When compared with fenofibrate, combination significantly decreased triglycerides and triglycerides/HDL cholesterol ratio. Otherwise, combination and fenofibrate significantly reduced apolipoprotein B and non-HDL cholesterol and improved flow-mediated dilation and reduced CRP and fibrinogen to a similar extent. Also, combination and fenofibrate significantly improved insulin sensitivity to a similar extent by reducing insulin and glucose in patients with hypertriglyceridemia. (C) 2016 Elsevier Ireland Ltd. All rights reserved.