Background: The aim of the present study was to investigate whether intra-aortic balloon pump (IABP) support was associated with better outcomes after rotational atherectomy (RA) in patients with multivessel disease and low left ventricular ejection fraction (LVEF). Methods: Between January 2015 and December 2021, 596 consecutive patients with severely calcified coronary lesions who underwent elective RA were retrospectively enrolled. Of these, a total of 156 patients were included in this study based on the propensity score matching and divided into two groups according to elective IABP insertion (IABP group, n = 80) or no insertion (non-IABP group, n = 76) before the RA procedure. The primary endpoints were procedural success and major adverse cardiovascular events (MACE) before discharge. The secondary endpoints were mortality and readmission due to heart failure (HF) during 90-day and 180-day follow-up. Results: 77 of patients (96.3%) in the IABP group and 72 of patients (94.7%) in the non-IABP group got procedural success (p = 0.714), separately. We had not observed significant differences in periprocedural complications except for less frequent hypotension in the IABP group (p 0.001). In-hospital MACE occurred in 7.5% of patients who received IABP support, which was significantly lower compared to the non-IABP group (p = 0.002). In addition, the cumulative incidence of readmission due to HF was also significantly lower in the IABP group during the 90-day (p 0.001) and 180-day (p = 0.004) follow-up. However, there were no significant differences between groups regarding the incidence of all-cause mortality. Conclusions: The present study suggests the important role of IABP support in improving the outcomes of patients after RA if multivessel disease and low LVEF are anticipated. Prophylactic IABP implantation was related to a lower incidence of in-hospital MACE, and readmission due to HF within 90-day and 180-day follow-up without significant impact on the procedural success and all-cause mortality.