A placebo controlled-blind study performed on new patients presenting with mild to moderate essential hypertension. A once daily combined dose of timolol maleate and bendrofluazide in a 4:1 ratio was administered ot each patient after a four week placebo period. The starting dose was timolol 10 mg and bendrofluazide 2-5 mg and this dose was increased in steps of timolol 10 mg and bendrofluazide 2-5 mg until blood pressure was controlled. Eleven out of twelve patients achieved normotension, the falls in diastolic and systolic blood pressure being highly significant on active treatment compared with placebo. The once daily regimen of timolol and bendrofluazide resulted in good control of blood pressure with no more side-effects than occurred on the placebo. A combination of these two drugs in one tablet would appear to be both practical and advantageous and should increase patient compliance in taking medication.