Pindolol is a new noncardioselective beta adrenergic blocking agent with intrinsic sympathomimetic activity. In the treatment of mild to moderate hypertension, pindolol provides effective control of blood pressure in a large majority of patients when administered alone or, more commonly, when combined with a thiazide diuretic. Pindolol is approximately as effective as propranolol in the therapy of hypertension, but in some crossover trials central nervous system side effects were more frequent with pindolol. A "ceiling effect" may be observed as dosages are titrated upward above approximately 20 to 30 mg per day, such that further blood pressure reductions may not be achievable. Some patients will exhibit a paradoxical increase in blood pressure with an increase in dosage. In patients who respond to modest doses of pindolol, twice or even once daily dosing is often adequate. This prolonged duration of hypotensive activity, while not suggested by the kinetics of this or similar drugs, is probably common to most beta blockers. Investigations in small numbers of patients with angina pectoris have reported variable but generally beneficial results with pindolol.