We compared the efficacy of Chinese traditional treatment for mild hypertension with that of a standard Western medical regimen in a group of 50 well-matched patients (24 allocated to Western medicine and 26 to Chinese traditional medicine) with mild hypertension (diastolic blood pressure 90-104 mmHg). Those receiving Western therapy were treated in a stepped-care fashion with dihydrochlorothiazide and atenolol. Those in the Chinese traditional therapy group received one of two mixtures of nine herbs and other ingredients, depending on symptoms at initial evaluation. Blood pressure dropped significantly in both groups after only a few days on therapy. After 19 days on treatment, the group receiving Western therapy had a fall in blood pressure from 168.2/96.3 mmHg to 137.3/76.7 mmHg (p less than 0.01), while those on Chinese traditional therapy fell from 168.2/95.9 mmHg to 146.4/80.5 mmHg (p less than 0.01). The fall in blood pressure was significantly greater, however, in those given Western therapy. The relief of existing symptoms or development of possible drug side effects was similar in both groups, except for nocturia, occurring more often in the group treated with Western therapy. We conclude that Western therapy is more effective in reducing blood pressure as compared with Chinese traditional therapy, but effective control of blood pressure in mild hypertensives is possible with either form of treatment.