Aim To investigate the effect of endogenous estrogen levels on vascular endothelial function and its mechanism in women with coronary heart disease (CHD). Methods Flow mediated dilatation (FMD) of the brachial artery were detected by use of high resolution ultrasound in 33 women with CHD and 17 matched controls. Plasma estradiol were measured by radioimmulogy. Plasma concentrations of asymmetric dimethylarginine (ADMA) were measured by high performance liquid chromatopraphy. Results In comparison with control group, FMD significantly decreased in the CHD group (1.73%±1.26% vs 5.37%±3.20%, p<0.001). Plasma estradiol levels were lower in the CHD group than in the controls (27.80±12.28 ng/L vs 43.83±14.30 ng/L, p<0.01), whereas ADMA concentrations were higher in the CHD group than in the controls (3.39±1.07 μmol/L vs 1.31±0.69 μmol/L,p<0.001). FMD was positively correlated with plasma estradiol levels (β=0.314, p<0.05), but negatively correlated with ADMA (β=0.302, p<0.05). Plasma estradiol levels inversely correlated with ADMA concentrations (r=-0.544, p<0.001). Conclusions This study indicates that endothelium dependent vasodilatation is impaired in women with CHD. The decrease of endogenous estrogen levels accompanied with the increase of ADMA concentrations may involve in one of the mechanisms of endothelial dysfunction in women with CHD.