A carotid-jugular fistula is a direct communication between the carotid artery and the jugular vein. Both congenital and spontaneous internal carotid-jugular fistulas are extremely rare. We describe the first case of successful endovascular treatment for a congenital internal carotid-jugular fistula. We report a 64-year-old woman who presented with a pulsatile mass swelling over the left cervical region and right hemiparesis after cough. Digital subtraction angiography confirmed the diagnosis of left high-flow internal carotid-jugular fistula. The fistula was successfully treated by fractional stent-assisted embolization.