To attain recent goals of blood pressure (BP) control, multiple drug therapy combinations are required, including higher doses of thiazide diuretics in combination with other classes of antihypertensive drug therapy. Thus, the authors evaluated the antihypertensive effects of telmisartan vs valsartan when combined with hydrochlorothiazide (HCTZ) 25 mg in a large (N=1066), placebo-controlled trial in patients with stage 1 or 2 hypertension. The primary end points were the changes from baseline in seated diastolic and systolic BP at the end of the 8-week treatment period. Safety end points included adverse events, changes in laboratory parameters, and pulse rate. Changes from baseline in BP following telmisartan-HCTZ (-24.0/-17.6 mm Hg) were significantly greater than both placebo (-4.4/-6.8 mm Hg) and valsartan-HCTZ (-21.2/-16.1 mm Hg) (vs placebo, P<.001 for systolic and diastolic BP; vs valsartan-HCTZ, P=.004 for systolic BP and P=.019 for diastolic BP). The total number of patients with at least 1 adverse event reported were similar among the 3 treatment groups (placebo, 49%; telmisartan-HCTZ, 43%; and valsartan-HCTZ, 38%). In conclusion, telmisartan-HCTZ at doses of 80/25 mg lowered both systolic and diastolic BP to a greater extent than valsartan-HCTZ at doses of 160/25 mg. These data support using a higher dose of a thiazide diuretic (25 mg) with a long-acting angiotensin receptor blocker as a useful strategy for improving hypertension control.