A girl aged 2 1/2 year on chronic hemodialysis, treated with converting enzyme inhibitor Captopril because of severe uncontrollable renal hypertension, returned for the first time to a satisfactory stable blood pressure. After three months of this therapy the bilateral nephrectomy was performed. Two weeks later the patient showed a stable blood pressure, normal for age. None of the known side effects was seen. Whether the oxalat deposits found with nephrectomy were due to the treatment with Captopril, cannot yet be answered.