Background Increased oxidative stress and vascular inflammation are main mechanisms for no reflow onset after acute ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (PCI).Recent studies have reported that the concentration of total bilirubin (TB), acted as antioxidant, could preserve coronary flow reserve and coronary microvascular functions and was reversely associated with in hospital outcomes of primary PCI.However, it is not clear whether high TB exert favorable effects on prognosis of no reflow patients during PCI.This study was performed to assess the prognostic role of TB in no reflow patients.