From January 2001 to July 2005, 4,741 cardiac catheterizations were performed on adult patients at our institute. Five of them underwent emergency operation due to complications of cardiac catheterization. The causes of operations were acute coronary occlusion due to coronary arterial dissection in 3 patients and bleeding due to perforation of the coronary artery in 2. Intra-aortic balloon pumping was used preoperatively in 4 patients and percutaneous cardio-pulmonary support in 2. Coronary artery bypass grafting was performed on all patients. Perforation sites of the coronary arteries were closed. One patient died 4 months after surgery, due to neurological damage, but the other 4 patients recovered and have been doing well. As coronary artery disruption is one of the main complications of cardiac catheterization, it is necessary to recognize the risk of hemodynamic derangement and to give prompt and appropriate treatment.