A 56-year-old Japanese man was admitted to our hospital with abdominal fullness in June 2006. He had been diagnosed as having a horseshoe kidney by computed tomography in January 2002. At that time, renal dysfunction (serum creatine: 2.0 mg/dl) was detected. Even after hemodialysis was started for end-stage renal failure in March 2006, his abdominal fullness became progressively worse. CT scanning showed a markedly enlarged horseshoe kidney. Transarterial embolization (TAE) was performed via the right renal arteries with 14 platinum microcoils; the left renal arteries were not embolized in order to preserve sufficient parenchyma and a urine volume of more than 1,000 ml daily. Two years after TAE, a decrease in the size of the left kidney was noted along with the right kidney. However, urine output was still more than 1,000 ml daily. It is possible that one kidney compressed the contralateral kidney, resulting in enlargement of both components of the horseshoe kidney and renal dysfunction. TAE may be a useful option for obstructive uropathy in patients with horseshoe kidney, which has conventionally been treated surgically.