A case of juxtaglomerular cell tumor of the right kidney is reported. A 30-year-old woman visited us with a complaint of headaches. Severe hypertension and an elevated level of plasma renin activity was seen at the initial evaluation. Computerized tomographic angiography revealed tumor vessels in the low-density mass in the right kidney. The preoperative diagnosis was renin-secreting tumor of the kidney, and nephron-sparing surgery was performed. The pathological findings showed a juxtaglomerular cell tumor. Postoperatively, prompt normalization of blood pressure and a reduced plasma renin activity level were observed.