A 60-year-old man was admitted to our department with a left renal artery aneurysm that was detected while performing an examination for dermatomyositis. A 3-dimensional image showed a saccular renal aneurysm whose diameter was 6 cm. He required operative intervention. Because of the location (near the renal hilum), selective transcatheter embolization using an interlocking detachable coil was performed for endovascular treatment. The postoperative course was uneventful. This method appears to be a good choice for the treatment of renal artery aneurysm, considering its safety and the likelihood of success.