The authors assessed the effect of an angiotensin receptor blocker (candesartan)-based regimen on electrocardiographic left ventricular hypertrophy (ECG-LVH) in 276 patients with hypertension, including 141 with the metabolic syndrome (MS). Baseline blood pressure (BP) and ECG-LVH parameters did not differ in patients with and without MS. At the study's end, BP had decreased similarly in both groups. At baseline, 26.1% of patients with MS and 24.7% without MS exhibited ECG-LVH by Cornell product (CorP) criteria (P=NS); 26.8% and 17.2%, respectively, by Sokolow-Lyon product (SokP) (P=.01); 11.4%and 11.8% by Cornell voltage (CorV) (P=NS); and 12.4% and 6.5% by Sokolow-Lyon voltage (SokV) (P=.01). At the study's end, in the MS group, prevalence of ECG-LVH was reduced to 19.5% from 26.1% (P=.001), to 8.5% from 11.4% (P=.01), and to 24.4% from 26.8%(P=.03) by CorP, CorV, and SokP, respectively. In patients without MS, only the CorP criterion showed a significant decrease in ECG-LVH prevalence, declining to 20.5% (P=.01). The relative risk reduction of ECG-LVH was higher in patients with MS according to CorV and SokP criteria (P<.01).