Two studies are presented on the possibility of treating hypertension with pindolol once daily. In the first one, patients already treated with multiple doses of pindolol, propranolol or alprenolol were shifted to single dose regime with pindolol, given in the morning. In most cases an adequate blood pressure control could be maintained on a dose of up to 20 mg pindolol. In the other study, previously untreated patients with mild to moderate hypertension were treated from the beginning with a single dose of pindolol. An adequate pressure control was also obtained in most of these patients with a dose not surpassing 20 mg pindolol once daily. In non-responders, the addition of a once daily dose of a diuretic resulted in an adequate pressure control. In both studies side-effects were few. The absence of sleep disturbances and beta-blocker induced bradycardia was particularly noteworthy.