BACKGROUND To evaluate the efficacy of prolonged intra-aortic balloon pumping (IABP) support in patients with cardiogenic shock following acute myocardial infarction (AMI). METHODS Thirty-nine patients with cardiogenic shock after AMI were treated with percutaneous coronary intervention which was supported by IABP. After 72 hours of IABP, the patients who attained the criteria of IABP withdrawal were randomly divided into two groups. The control group ceased IABP whereas the study group continued IABP for additional seven days. RESULTS After IABP, mean arterial pressure, cardiac index, left ventricle ejection fraction and arterial oxygen saturation were significantly elevated in all patients whereas pulmonary capillary wedge pressure and heart rate were decreased. The improvement of cardiac index, left ventricular ejection fraction and pulmonary capillary wedge pressure in the study group was greater than the control group (P<0.05). After 12-month follow-up, the 6-min walking test and left ventricular ejection fraction in the study group were significantly higher than those of the control group (P<0.05). No significant differences were noted between the two groups in the incidence ventricular aneurysm and mortality rate. CONCLUSIONS Prolonged use of IABP for up to 10 days offers additional long term benefit in left ventricular function and exercise tolerance.