A total of 16,350 patients underwent cardiac catheterization from January 1981 to December 1987. The brachial artery was used in 10,500 patients (group I), and the femoral artery was used in 5850 patients (group II). Surgical intervention for complications was necessary in 60 (0.57%) of the group I patients and in 14 (0.23%) of the group II patients. Hand ischemia in group I and bleeding in group II were the most frequent indications for operation. Procedures performed were segmental resection, vein interposition, and long bypass in group I, and simple suture and angioplasty were performed in group II. Fifty-six patients of the total of 74 underwent early repair (within 48 hours), and 18 patients underwent delayed intervention. Only one (1.7%) of the 56 patients who had early repair had a complication. Five of the 18 patients (28%) with delayed intervention suffered significant complications. Cardiac catheterization by the brachial or femoral route has a low incidence of complications. Delayed intervention is associated with high morbidity despite adequate restoration of circulation. Although there were fewer complications in the femoral group, they were far more serious with respect to life- or limb-threatening events.