Aim To observe the carotid intima-media thickness (IMT) and plaque in patients with hypertension and insulin resistance. Furthermore to investigate the correlation between asymmetric dimethylarginine (ADMA) and carotid atherosclerosis in patients with insulin resistance. Methods Sixty patients with essential hypertension were recruited. According to the level of homeostasis model assessment (HOMA),thirty-five patients were classified as essential hypertension with insulin resistant (EH with IR),and twenty-five as essential hypertension without insulin resistant (EH without IR). Another 20 healthy individuals were selected as the control groups. HOMA-IR was calculated as a measure of insulin resistance. Serum concentrations of ADMA levels were measured by the high-performance liquid chromatography method. Carotid IMT and plaque were measured by high-resolution ultrasonography. Result Common carotid artery IMT(CCA-IMT) in patients of EH with IR were higher than those in EH without IR and controls (P<0.05,P<0.01),the incidence of carotid plaques was also higher than that in controls (P<0.05). Serum levels of ADMA were significantly increased in EH with IR as compared with those in EH without IR and controls (P<0.01),the levels of ADMA in EH without IR were much higher than those in controls (P<0.01). In patients with hypertension,both CCA-IMT and serum levels of ADMA had positive correlations with insulin resistance (r=0.306 and r=0.370,P<0.01). Serum levels of ADMA closely correlated with the CCA-IMT (r=0.381,P<0.01),and this correlation remained significant even on multiple regression analysis. Conclusion Increased serum ADMA level may play a role in progression of early atherosclerosis in patients of hypertension with insulin resistance.