The antihypertensive effect of acebutolol was observed in 26 cases of essential hypertension, and following results were obtained. 1) Mean decrease in systolic and diastolic blood pressure by oral acebutolol was 21mmHg and 11mmHg. The results of antihypertensive therapy revealed good control in 30.8%, fair control in 34.6%, poor in 11.5% and failure in 23.1% of the cases. In 65.4% of the cases, good or fair control of hypertension which means drop of diastolic pressure to the level of less than 100mmHg was observed. 2) Mean drop in heart rate was 7/min. 3) Average daily dose was 508+/-171.9mg. 4) The side effect of oral acebutolol was mild gastrointestinal discomfort in two cases.