There are important pharmacodynamic differences between the various beta-adrenoceptor-blocking drugs, whereas the angiotensin-converting enzyme (ACE) inhibitors differ mainly in their pharmacokinetic properties. The differing properties of the beta-blocking drugs may contribute to their antihypertensive effect; possibly, the beta1-selective agents are slightly more effective. Comparisons between groups of drugs may not be fully applicable to all members of the group. Overall, however, beta-blocking drugs and ACE inhibitors appear to control the resting blood pressure to a similar degree, whereas on exercise the rise in blood pressure is inhibited to a greater extent by beta1-blockade. ACE inhibitors reverse the hemodynamic changes of hypertension in contrast to beta1-blocking drugs without intrinsic sympathomimetic activity (ISA). Neither group of drugs interferes with cardiovascular reflexes such as the response to posture. The beta-blocking drugs have specific contraindications such as asthma and heart failure. Although some earlier studies suggested otherwise, more recent smaller investigations suggest that overall patient acceptability of ACE inhibitors and beta-blockers is similar. In certain instances, particularly in the presence of diuretics, a large first-dose effect with a profound fall in blood pressure may be seen with ACE inhibitors. In contrast to other drugs, there is some evidence that beta-blocking drugs have a cardioprotective effect. ACE inhibitors and beta-blocking drugs have a similar spectrum of activity, with black patients responding less well. Although in dispute, drugs are often useful in the elderly. Both groups possess additional therapeutic indications that may influence the choice to treat hypertension.