Antithrombotic and antiplatelet therapies have been the focus of extensive clinical investigations over the past 2 decades. In PCI settings all therapies inhibiting coagulation and primary hemostasis may limit ischaemic event rates, but are associated with an increased risk of bleeding. Retrospective and registry data indicates that haemorrhage is associated with mortality in patients undergoing PCI, emphasizing the potential importance of minimizing bleeding, as well as ischemic events, bleeding has now emerged as one of the most common complication of PCI. Major bleeding and blood transfusion have been strongly associated with increased rates of in-hospital and late mortality, MI and repeat revascularization after PCI. Also minor bleeding, although represent a complication significantly less dangerous than major haemorrhages, are associated with prolonged hospitalization, increased cost and adversely affect short- and long-term outcome.