Forty-five patients with diastolic blood pressure (DBP) greater than or equal to 105 mmHg were randomly assigned to receive Western (group 1, n = 21) or a classical Chinese herbal preparation (group 2, n = 24) to treat their hypertension (HBP). All remained hypertensive after 4 days in the hospital without treatment. Except for baseline Na+ excretion (higher in group 1) and somewhat more evidence of end organ damage in group 1, the patient groups were comparable. Those in group 1 were given a thiazide diuretic and propranolol if needed, and those in group 2, a mixture of 12 herbs. Patients on active therapy in group 1 had a drop in blood pressure (BP) from 172.6 +/- 27.8/107.4 +/- 13.6 to 141.2 +/- 26.2/89.6 +/- 12.0 mmHg, whereas those in group 2 had no change in BP, 168.8 +/- 22.0/107.7 +/- 9.8 mmHg to 165.7 +/- 23.7/106.0 +/- 11.8 mmHg. Although 66% of patients in group 1 had a DBP under 90 mmHg by discharge, only 8% of those in group 2 did. Except for a fall in serum K+ in group 1, there were no significant biochemical or clinical problems in either group. We conclude that standard Western medication is more effective than a classical Chinese herbal preparation used to treat HBP.