Since it has been suggested that the renin-angiotensin axis may play an important role in the severe hypertension and in the acute renal deterioration in scleroderma, we sought to determine the effectiveness of angiotensin blockade in the treatment of this disorder. Captopril controlled blood pressure successfully and easily in 4 consecutive patients with scleroderma renal crisis. Mean serum creatinine was 3.5 mg/dl after scleroderma renal crisis immediately prior to captopril. The first patient required maintenance hemodialysis because of progression to advanced renal failure before captopril was available. However, in this patient oliguric renal failure was changed to nonoliguric renal failure immediately after beginning therapy. Serum creatine stabilized in the other 3 patients. Serum creatinine peaked at 4.7 mg/dl, but then progressively improved to 3.5 mg/dl 12 weeks after captopril was begun. None of the other 3 patients required any form of dialysis during the scleroderma renal crises. Mean survival of these 4 patients was significantly greater than that of the 9 previous patients with scleroderma crisis. These observations confirm that angiotensin blockade with captopril is effective therapy to prevent renal deterioration, to control blood pressure and prolong survival in scleroderma patients with renal crisis.