Aim To determine endothelial function and chemokine activity of peripheral blood monocytes in individuals with primary hypertension, and to explore the role of asymmetric dimethylarginine in this process. Methods 42 patients with essential hypertension and 40 healthy controls in the out-patient clinic and admission department of the hospital were enrolled in the present study. Flow-mediated dilation on brachial artery was assessed and the plasma levels of asymmetric dimethylarginine and monocyte chemoattractant protein-1, and the expression of CCR2 protein expression in peripheral blood mononuclear cells were also determined. Results Endothelial dysfunction were found in patients with primary hypertension, manifesting that flow-mediated dilation was decreased, the levels of asymmetric dimethylarginine were elevated, and the levels of nitric oxide were decreased (P<0.05). Compared with controls, plasma levels of monocyte chemoattractant protein-1 were markedly elevated and the expression of CCR2 protein in separated peripheral blood mononuclear cells in hypertensive patients was significantly upregulated (P<0.05). Incubation of mononuclear cells with exogenous asymmetric dimethylarginine (30 μM) for 24 h further upregulated the expression of CCR2 protein in hypertensive patients (P<0.05). Conclusions Asymmetric dimethylarginine may promote endothelial dysfunction and activation of monocytes existed in patients with essential hypertension.