The metabolic syndrome is strongly associated with insulin resistance and consists of a constellation of factors such as hypertension and hyperlipidemia that raise the risk for cardiovascular diseases and diabetes mellitus. There is widespread agreement that the renin-angiotensin system (RAS) plays a pivotal role in the pathogenesis of insulin resistance and cardiovascular disease in diabetes. Indeed, large clinical trials have demonstrated substantial benefit of the blockade of this system for cardiovascular end-organ protection. Thus the blockade of the RAS may be a promising strategy for the treatment of the patients with the metabolic syndrome. Although several types of angiotensin II type 1 (AT(1)) receptor blockers (ARBs) are commercially available for the treatment of patients with hypertension, we have recently found that telmisartan (Micardis) could have the strongest binding affinity to AT(1) receptor. Further, telmisartan is reported to act as a partial agonist of peroxisome proliferator-activated receptor-gamma (PPAR-gamma). These observations suggest that, due to its unique PPAR-gamma-modulating activity, telmisartan may be one of the most promising sartans for the treatment of cardiometabolic disorders. In this paper, we reviewed the potential utility of telmisartan in insulin resistance and vascular complications in diabetes.