Background: Studies correlating intravascular ultrasound (IVUS) and clinical findings have suggested that positive remodeling (PR) in culprit lesions is more associated with acute coronary syndromes (ACS) and events post-intervention. And, serum inflammatory markers can predict future risk of acute coronary events in patients with ACS. Methods: We sought to elucidate the relationship of serum inflammatory markers with IVUS estimation of coronary artery remodeling in patients with non-ST segment elevation ACS. Eighty five patients at our institution undergoing IVUS-assisted percutaneous coronary intervention with non-ST segment elevation ACS were included. PR was defined as remodeling index (RI, lesion/reference external elastic membrane cross-sectional area >1.05 and negative remodeling (NR) as <0.95. Results: RI was 1.12짹0.06 in PR group (n=45) and 0.84짹0.09 in NR group (n=40). The plaque burden and follow-up percent neointimal hyperplasia area were greater in PR group than in NR group (72짹6% vs. 67짹9%, p=0.017 and 35짹16% vs. 25짹14%, p=0.020). Baseline high-sensitivity C-reactive protein and fibrinogen levels were significantly higher in PR group than in NR group (1.99짹3.37 mg/dl vs. 0.61짹0.98 mg/dl, p=0.030 and 293짹39 mg/dl vs. 248짹61 mg/dl, p=0.003). RI was positively correlated with baseline plaque burden and follow-up percent neointimal hyperplasia area (r=0.421, p<0.001 and r=0.310, p=0.004, respectively) and was positively correlated with baseline high-sensitivity C-reactive protein and fibrinogen levels (r=0.302, p=0.019 and r=0.441, p<0.001, respectively). Conclusions: Positive coronary artery remodeling correlates positively with the levels of inflammatory markers and neointimal hyperplasia in patients with non-ST segment elevation ACS. So, strong anti-inflammatory therapy such as statins is needed for positively remodeled patients with non-ST segment elevation ACS.