We discuss combination therapy with angiotensin receptor antagonists (angiotensin receptor blockers; ARBs) and thiazide diuretics in light of the independent actions of both types of agents, and the adverse effects of both agents independently and in the context of the physiologic synergy achieved in using these agents together. ARBs counteract many of the adverse events associated with the use of thiazide diuretics and have been shown to reduce the occurrence of new-onset diabetes mellitus. We also review outcome trials in patients with hypertension (such as LIFE [Losartan Intervention For Endpoint reduction in hypertension], VALUE [Valsartan Antihypertensive Long-term Use Evaluation], and SCOPE [Study on COgnition and Prognosis in the Elderly]), in which losartan, valsartan, and candesartan cilexetil were used in combination with hydrochlorothiazide. Fixed combination ARB/hydrochlorothiazide agents make sense as initial therapy for patients in whom BP is >20/ 10mm Hg above goal.