An optimal antihypertensive drug produces superior blood pressure-lowering effects at established dosages, with an acceptably low incidence of side effects, and at a dosage interval that is convenient for patients (ideally, once daily). The angiotensin II receptor antagonist, telmisartan, meets these criteria. At doses of > or = 40 mg, this once-daily drug produces a statistically significant reduction in blood pressure. Ambulatory blood pressure monitoring (ABPM) and high trough-peak ratios attest to the smooth, consistent blood pressure-lowering effect of telmisartan at 40- and 80-mg dosages. Telmisartan also demonstrates a statistically superior antihypertensive effect toward the end of the dosing interval compared with amlodipine and losartan, and it has a side-effect profile comparable to that of placebo. In summary, the evidence suggests that telmisartan at dosages of 40 and 80 mg once daily satisfies the 3 criteria of an ideal antihypertensive agent, producing an effective and sustained response with placebo-like tolerability.