Objectives: RCT results of effect of fish oil on aortic stiffness are inconclusive. The aim of this study is to examine the differential association of EPA and DHA with aortic stiffness measured as cfPWV in Korean men in South Korea where fish intake is much higher than in the US (70 g/day vs. 7 g/day, respectively), and in White and Japanese American men. Methods: The ERA JUMP Study is a population-based study of atherosclerosis in men aged 40-49 free of CVD in Japan, Korea, and the US. The study examined cfPWV in 298 Koreans, 298 Japanese Americans and 263 Whites in 2002-07 using an automated waveform analyzer (VP2000, Omron, Japan). Serum EPA and DHA were measured using gas chromatography. Other variables including BP, heart rate, lipids, BMI, smoking and alcohol were measured using standardized methods. Multiple regression analysis was used to examine the association of each of EPA and DHA with cfPWV after adjusting for confounders. Results: Mean (SD) cfPWV (cm/sec) in Koreans was significantly lower than the other two groups (810 (130), 863 (213), and 902 (208), for Koreans, Whites, and Japanese Americans, respectively). Mean (SD) EPA (%) in Koreans was significantly higher than that in the other two groups (1.9 (1.0), 0.8 (0.6), and 1.0 (0.9) for Koreans, Whites, and Japanese Americans, respectively). Similarly mean (SD) DHA (%) in Koreans was significantly higher than that in the other two groups (4.8 (1.4), 2.4 (1.2), and 3.2 (1.4) for Koreans, Whites, and Japanese Americans, respectively). Multiple regression analyses showed that cfPWV in Koreans had a significant inverse association with EPA after adjusting for age, systolic BP, and heart rate, which remained after further adjusting for other potential confounders ( Table ). In contrast cfPWV in Koreans did not have a significant association with DHA. Meanwhile cfPWV in Whites or Japanese Americans did not have a significant association with either EPA or DHA. Table Multivariate adjusted association of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with aortic stiffness measured as carotid-femoral Pulse Wave Velocity Koreans in South Korea (n=298) Whites (n=263) Japanese Americans (n=280) Standardized beta P Standardized beta P Standardized beta P EPA Model I −0.141 0.010 0.018 0.759 −0.078 0.213 Model II −0.138 0.012 0.035 0.536 −0.013 0.827 Model III −0.150 0.007 0.037 0.529 −0.037 0.528 DHA Model I −0.086 0.112 0.012 0.840 −0.066 0.239 Model II −0.084 0.124 0.050 0.397 −0.039 0.696 Model III −0.089 0.103 0.052 0.392 −0.009 0.881 Model I: adjusted for age, systolic blood pressure and heart rate Model II: further adjusted for body mass index, current smoking, alcohol drinking, and medication for blood pressure Model III: further adjusted for LDL-C, HDL-C, triglycerides, diabetes, medication for lipid Conclusions: Our results suggest that high levels of EPA observed in Koreans have a favorable effect on aortic stiffness.