The cone artery, or artery of Desproges-Gotteron, is sometimes seen arising from the internal iliac artery. The authors describe a case of a symptomatic perimedullary arteriovenous fistula (AVF) of the conus medullaris in an 8-year-old boy who presented with a protracted history of urinary difficulty and severe sudden-onset right lumbosciatic pain that evolved to severe paraparesis with compromise of the sphincter muscles. The spinal AVF, which was supplied by the cone artery and a thoracic radiculomedullary artery that joined at the fistula site in a large partially thrombosed varix, was completely occluded with Onyx liquid embolic. The patient's clinical condition improved rapidly after embolization. As shown in this patient, urgent endovascular embolization of spinal AVFs can be very rewarding, even in patients with severe neurological presentation. The artery of Desproges-Gotteron appears to be a rare arterial variation. To the authors' knowledge, this is the first pediatric case of a conal AVF supplied by this artery.