Hypertriglyceridemia is often associated with small dense low density lipoprotein (LDL), elevated remnants, and decreased high density lipoprotein (HDL)-cholesterol (C), which comprise the dyslipidemic triad. The objective of this study was to investigate the effect of fenofibrate on the lipoprotein subfraction profile and inflammation markers in hypertriglyceridemic men. Twenty hypertriglyceridemic men were administered fenofibrate, 200 mg daily, for 8 weeks. Lipoprotein subclasses were measured by nuclear magnetic resonance (NMR) spectroscopy. Inflammation markers including C-reactive protein (CRP), interleukin-6 (IL-6), and monocyte chemotactic protein-1 (MCP-1) were also determined. Fenofibrate lowered triglyceride (TG) by 58% and increased HDL-C by 18%. NMR analysis revealed that very low density lipoprotein (VLDL), particularly large VLDL, intermediate density lipoprotein (IDL), and small LDL, were significantly decreased, and LDL distribution shifted towards the larger particles. HDL distribution was altered; there was an increase in small HDL and a decrease in large HDL, resulting in a significant decrease in HDL particle size, from 9.1 to 8.9 nm, as well as a 27% increase in HDL particle number. Among inflammation markers, CRP was significantly decreased by 42%. In conclusion, fenofibrate effectively improves atherogenic dyslipidemia by reducing remnants and small LDL, as well as by increasing HDL particles. These effects, together with the favorable effect on inflammation, might provide a clinical benefit in hypertriglyceridemic subjects. J Atheroscler Thromb, 2004; 11: 278-285.