Chronic unilateral hematuria is characterized by intermittent or continuous hematuria that cannot be diagnosed using standard radiologic and hematologic methods. Unilateral hematuria is probably a benign condition that seldom requires surgical treatment, but some cases such as massive or chronic bleeding were needed partial or total nephrectomy. Recently, a variety of treatments, including the upper urinary tract endoscopic interventions have been attempted if the bleeding focus is identified. However, when the bleeding focus is not identified on ureteroscopy, surgical treatment has been considered a priority. We report a case of chronic unilateral hematuria treated with segmental renal artery embolization. A 42-year-old woman has intermittent gross hematuria and anemia for 31 months. About 29 and 19 months ago, she already underwent CT urography, renal angiography, retrograde pyelography, and renal biopsy at other hospitals, but didn't find any other specific abnormalities except some blood clots in the left renal pelvis on ureteroscopy. She underwent CT urography, renal angiography, cystoscopy, and ureteroscopy again. Ureteroscopic findings only showed bleeding in the upper third of left renal calyces but a definite bleeding focus could not be identified. Thus, we decided to manage with segmental renal artery embolization rather than partial nephrectomy to minimize renal function reduction and avoid operational risk. The superior and superoanterior segmental renal arteries were successfully embolized with 3mm coils and gelatin sponge.[figure1] Gross hematuria disappeared on the 4th day after the procedure. Microscopic hematuria disappeared on the 5th day. Infarction in the upper portion of left kidney was confirmed on CT scan on the 11th day.[figure2] Thereafter serial urinalysis showed no hematuria. Patients with chronic unilateral hematuria often require surgical or upper urinary tract endoscopic procedures. Segmental renal artery embolization will be a better treatment option for patients unable to identify the bleeding focus on the upper urinary tract endoscopy.