We determined the location of arterial injury in 11 patients who had pseudoaneurysms with (six cases) or without (five cases) arteriovenous fistula as a complication of cardiac catheterization. Medical records and arteriograms were examined retrospectively. Ten of the 11 pseudoaneurysms identified were located below the level of the femoral head. Five of six patients with arteriovenous fistula had simultaneous catheterization of both the femoral artery and the femoral vein. Although we did not determine the location of arterial puncture used in uncomplicated angiograms during the 5-year study period, our experience in 11 patients with pseudoaneurysms with or without arteriovenous fistula suggests that there is an association between a puncture site below the level of the femoral head and arterial injury. In addition, arteriovenous fistulas appear to be associated with simultaneous catheterization of the femoral artery and adjacent femoral vein.