Anterior tibial artery aneurysms (ATAAs) are relatively rare entities. Most ATAAs are pseudoaneurysms resulting from trauma, infection, or iatrogenic injury. We observed a 33-year-old woman with a huge true ATAA who did not have any potential cause of pseudoaneurysm or risk factors for atherosclerosis or connective tissue disorder.Endovascular isolation by the bi-directional approach was successfully performed, and the ATAA was totally excluded from the afferent blood flow. Distal flow of the anterior tibial artery was preserved, and pulsation of the dorsal pedis artery was also well preserved. Her postoperative course was uneventful, and follow-up ultrasonography and magnetic resonance imaging revealed the ATAA shrinkage.