We reported a case of an abdominal wall hematoma which caused by Seldinger method via the femoral artery. A 48-year-old female, suffered from direct carotid cavernous fistula, was treated by transfemoral transvenous embolization (TVE). The whole procedure was completed without difficulty except minor resistance of guide wire manipulation during left femoral artery catheterization. Four hours later, the patient became hypotensive and showed the sign of impending shock without definitive causes. Nine hours after the embolization a huge hematoma of the abdominal wall was found. It required the total 1200 m/ of blood transfusion before her blood pressure returned to normal. She recovered fully from this event and discharged uneventfully. There is a speculation that a deep circumflex iliac artery (DCIA) was injured with an angle-shaped guide wire and bled into the abdominal wall. And subsequent systemic heparinization prevented the coagulation process, resulting a large hematoma. Anatomically, an angle-shaped guide wire is easily able to migrate into DCIA. To prevent a vascular injury, it is very important to manipulate a guide wire under fluoroscopic control and to select a J-shaped guide wire instead of an angle-shaped one.