Objective: To investigate the in-hospital mortality rate of STEMI patients treated with IABP according to different TIMI risk scores (TRS). Methods: The clinical data of 897 consecutive ST-segment elevation myocardial infarction (STEMI) patients, without mechanical complications, from July 2005 to July 2013, were retrospectively analysed. The in-hospital outcomes were compared for the 293 patients with intra-aortic balloon pumps (IABPs) versus those without, using the thrombolysis in myocardial infarction risk score (TRS) for risk stratification. Results: According to the ROC curve results for TRS, patients were divided into three risk stratifications. Patients with IABP support had a lower in-hospital mortality (4.3% versus 12.2%, P = 0.011) for TRSs of 4-8. However, there was no significant difference between the two groups in other risk stratifications. Univariate logistic regression analysis indicated a significant association between IABP and in-hospital mortality in patients with TRSs of 4-8 (OR: 0.326, 95% CI: 0.136-0.786, P = 0.013). After propensity stratification analysis, there was still a significant difference in the odds for mortality (OR: 0.357, 95% CI: 0.143-0.889, P = 0.027). Conclusions: IABP support may be more effective in reducing in-hospital mortality for STEMI patients whose hemodynamics is compromised with a TRS of 4-8.