Congenital carotid-jugular (CJ) fistula of the neck is a very rare clinical entity that has various causes. The CJ fistulas are particularly prone to complications unlike other peripheral arteriovenous fistulas. The aim of this report is to present a case of a CJ fistula between the external carotid and the external jugular vein, which was successfully closed with detachable balloon by an endovascular approach. A 14-year-old child was admitted to our clinic with a pulsatile neck swelling. There was no previous history of trauma. A high-flow fistula between the external carotid and the external jugular vein was determined. The fistula was closed with detachable balloon by an endovascular approach. The postoperative angiogram demonstrated complete resolution of the fistula. Endovascular treatment of CJ fistulas with detachable balloons is a safe and less traumatic technique and may be an effective alternative to the open surgery in selected patients.