Background Transradial access has been increasingly used during primary percutaneous coronary intervention (PCI)for patients with acute ST-segment elevation myocardial infarction (STEMI) in last decade.Clinical benefits of upstream use of tirfiban therapy in STEMI patients treated by primary PCI have been reported.We investigated the merits of transradial vs.transfemoral access in primary PCI for STEMI patients with upstream use of tirofiban.Methods Patients with STEMI treated with tirofiban between December 2006 and October 2012 then by primary PCI were compared between transradial (n=298) and transfemoral (n=314) access.Baseline demographics,angiographic and PCI features and primary endpoint of major adverse cardiac events (MACE) at 30-day clinical follow-up were recorded.Results Baseline and procedural characteristics were comparable between the two groups,apart from more patients in transradial group had hypertension and were treated by thrombus aspiration during primary PCI.Significantly fewer MACE occurred in the transradial group (5.4％) compared with the transfemoral group (9.9％) at 30-day clinical follow-up.Major bleeding events at 30-day clinical follow-up were 0 in transradial group and in 2.9％ of transfemoral group.Multivariate analysis confirmed transradial approach as an independent negative predictor of 30-day MACE (HR 0.68;95％ CI 0.35-0.91; P=0.03).Conclusions Using transradial approach in primary PCI for acute STEMI infarction patients treated with tirofiban was clearly beneficial in reducing bleeding complications and improving 30-day clinical outcomes.