Introduction:The aim of this study was to investigate The effect of quercetin supplementation on oxidative stress, blood pressure, aerobic power, level of concentric pathologic hypertrophy and cardiac function in men with hypertension and CAD after PCI.\nMethods:The current study was a randomized double-blind clinical trial in which 24 men with hypertension and CAD after PCI aged 40-60 years, were participated. Patients were assigned into quercetin (250 mg/day) or placebo groups for 8 weeks. Plasma TAC and malondialdehyde (MDA) using colorimetric method, LVDD, PWd, EF and E/A using Echocardiography, WRp using the Storer-Davise Cycle Test and also blood pressure were measured at the beginning and end of intervention. Data were analyzed using paired-sample T-test and ANCOVA.\nResults:supplementation generated significant improvement in oxidative stress reduction(TAC increased and MDA decreased), systolic and diastolic blood pressure, systolic(EF) and diastolic(E/A) function and aerobic power compared to the pre test and the placebo group following eight weeks of treatment (p < 0.05). also, A small decrease in RWT was observed in quercetin group at the end of intervention, but it was not statistically significant (P = 0.132). Also, The RWT were not significantly different between groups (P = 0.52).\nConclusion: quercetin supplementation can improve the oxidative stress, blood pressure, left ventricular function and aerobic power in men with hypertension and CAD after PCI. Whereas have no effect on level of concentric pathologic hypertrophy. Further studies are needed to ensure the effect of quercetin on Left ventricular hypertrophy in human.