Two groups of patients with hypertension ( n = 16 and 20) with comparable average age and degree of severity of clinical hypertension were controlled in an ambulatory long-term investigation for 18 months. While one group was treated with an antihypertensive standard therapy, the other group got a fixed combination of dihydralazin and propranolol. In both groups a significant decrease of the systolic and diastolic initial blood pressure was seen, which was more pronounced in the second group. Side-effects of drugs more frequently appeared in the first group. On the other hand, the total cost were higher in the second group. Nevertheless, the stronger effect, the smaller number of tablets as well as the lower rates of side-effects pleads for the combination dihydralazin-propranolol.