BACKGROUND AND OBJECTIVES: Non-high density lipoprotein-cholesterol (non-HDL-C) and apolipoprotein B (ApoB) are markers of atherosclerotic risk and predictors of cardiovascular events. The aim of this study was to evaluate clinical impact of non-HDL-C and ApoB on clinical outcomes in metabolic syndrome (MS) patients with acute myocardial infarction (AMI) undergoing percuatneous coronary intervetion. SUBJECTS AND METHODS: We analyzed 470 MS patients (64.4+/-12.0 years, 53.6% male) with AMI who were followed-up for 12-month after percutaneous coronary intervention (PCI) from December 2005 to January 2008 in a single center. These patients were divided into 2 groups based on median values of non-HDL-C and ApoB. We studied their baseline and follow-up relation with 12-month clinical outcomes, all-cause death and major adverse cardiac events (MACE). RESULTS: Mean values of baseline non-HDL-C and ApoB were 141.2+/-43.1 mg/dL and 99.3+/-29.0 mg/dL respectively. During 12-month follow-up 32 MACE (6.8%) and 12 deaths (2.5%) occurred. We observed significant correlation between non-HDL-C and ApoB. Twelve-month MACE and all-cause death after PCI showed no significant relation as non-HDL-C or ApoB levels increased. Follow-up patients (n=306, rate 65%) also did not show significant relation with clinical outcomes. Twelve-month MACE decreased as non-HDL-C and ApoB reduction rates increased. CONCLUSION: There was no significant association between higher non-HDL-C or ApoB and 12-month clinical outcomes in MS patients with AMI undergoing PCI. ApoB was found to be a better predictor of 12-month MACE than non-HDL-C based on their reduction rates.