Aim To investigate the effect of telmisartan on adiponectin in hypertensive patients with type 2 diabetes mellitus. Methods In this prospective study,50 hypertensive patients with type 2 diabetes mellitus were treated either with telmisartan or with amlodipine for 10 weeks.The serum concentration of fasting adiponectin,glucose,insulin and blood pressure(BP) were measured at baseline and after treatment respectively. Results The systolic and diastolic BP decreased significantly after the treatment both in telmisartan group and in amlodipine group.In telmisartan group,serum adiponectin was significantly increased,but blood glucose,insulin and insulin resistance(IR) were significantly decreased(P<0.01);But no notable difference was detected in adiponectin,blood glucose,insulin in amlodipine group(P>0.05). Conclusion These data indicated the potential effect of telmisartan on the improvement of adiponectin and IR,which demonstrate the metabolic effect of telmisartan beyond its BP reduction.