In 5 cases of profound left ventricular failure, simultaneous application of a percutaneous cardiopulmonary support system (PCPS) in which the entire circuit was coated with heparin, and intra-aortic balloon pumping (IABP) were performed. No case responded to therapy consisting of large amounts of inotropic agents, followed by IABP. With the assistance of the PCPS (mean flow rate 2.3l/min) combined with moderate doses of inotropic agents and IABP, the hemodynamics of all 5 patients were stabilized. Using low amounts of heparin, the activated coagulation time during PCPS was maintained between 150 and 200 seconds. No complications directly related to this procedure such as thromboembolism and bleeding were observed. Four cases have been successfully weaned from the PCPS. Of the four, two cases are long-term survivors and are currently functioning normally in society. At present, the indications, optimum parameters for PCPS flow rate, and when to start weaning from the PCPS have not been established. However, we conclude that simultaneous use of PCPS and IABP is useful to maintain adequate systemic circulation in cases not responding to medication and IABP.