To compare the effectiveness of a fenofibrate 145-mg nanoparticle tablet formulation with the standard 160-mg tablet in patients with dyslipidemia and coronary heart disease. Retrospective medical record review. Outpatient university-affiliated cardiology clinic. One hundred thirty patients with dyslipidemia and coronary heart disease treated for a minimum of 6 months with fenofibrate 160 mg/day (with or without 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor [statin] therapy) who were then switched to a minimum of 3 months of treatment with fenofibrate 145 mg/day. Low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglyceride levels were compared during treatment with each formulation. In patients not taking statins, statistically significant reductions of 4.6% and 2.3%, respectively, were noted in mean triglyceride and LDL levels after the switch to fenofibrate 145 mg/day. In patients taking statins, statistically significant reductions of 5.1% and 2.8%, respectively, were observed in mean triglyceride and LDL levels. In total, a larger proportion of patients had 10% or greater improvement in LDL (14/130 [11%]) and triglyceride (32/130 [25%]) levels compared with the proportion of patients who had 10% or greater worsening in LDL (3/130 [2%]) and triglyceride (9/130 [7%]) levels, and a net additional 14 patients (11%) achieved National Cholesterol Education Program (NCEP) lipid panel targets after the switch to fenofibrate 145 mg/day. Mean HDL level was not significantly different after the switch to fenofibrate 145 mg/day. Safety parameters of fenofibrate 145-mg/day therapy were not examined, although fenofibrate 160 mg/day is generally well tolerated. Eleven percent of the patients in our study had improvements in their lipid profiles that resulted in achievement of NCEP lipid panel targets after treatment with the 145-mg nanoparticle formulation of fenofibrate. This improvement in lipid levels may have been related to increased bioavailability of the 145-mg formulation. However, the exact mechanism of the improvement in lipid levels is unknown.