Background The role of intraaortic balloon pump (IABP) during percutaneous coronary intervention (PCI) in high-risk acute patients remains debated. Device-related complications and the more complex patient management could explain such lack of clinical benefit. We aimed to assess the impact of transradial versus transfemoral access for PCI requiring IABP support on vascular complications and clinical outcome. Methods We retrospectively analyzed 321 consecutive patients receiving IABP support during transfemoral (n = 209) or transradial (n = 112) PCI. Thirty-day net adverse clinical events (NACEs) (composite of postprocedural bleeding, cardiac death, myocardial infarction, target lesion revascularization, and stroke) were the primary end point, with access-related bleeding and hospital stay as secondary end points. Results Cardiogenic shock and hemodynamic instability were the most common indications for IABP support. Cumulative 30-day NACE rate was 50.2%, whereas an access site-related bleeding occurred in 14.3%. Patients undergoing transfemoral PCI had a higher unadjusted rate of NACEs when compared with the transradial group (57.4% vs 36.6%, P