Although numerous prospective randomized trials since the Veterans Administration studies clearly have attested to the efficacy and safety of antihypertensive therapy, there remain some controversial issues with all classes of antihypertensive drugs. Thiazide diuretics increase the risk for new-onset diabetes and their long-term safety has been questioned. Alpha-blockers do not reduce morbidity and mortality in uncomplicated hypertension but are well known to cause a variety of poorly tolerated side effects. The safety of calcium antagonists has been questioned for many years, although recent large prospective randomized trials such as Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, International Verapamil-Trandolapril Study, Intervention as a Goal in Hypertension, Valsartan Antihypertensive Long-Term Use Evaluation and the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) have attested to their safety and efficacy. Angiotensin-converting enzyme inhibitors, in general, are well tolerated but have potentially fatal adverse effects in a few patients. Angiotensin-receptor blockers are exceedingly well tolerated, but may be less-efficacious antihypertensive agents than other drug classes. Most antihypertensive drug classes have an effect on new-onset diabetes that should be taken into account in patients at risk. No head-to-head comparison of combination therapy looking at efficacy and safety has been available. The long-term safety of antihypertensive therapy is documented poorly because most trials only last 4 to 6 years. Despite these drawbacks and concerns, the benefits of antihypertensive therapy clearly outweigh its potential risk.