Recent studies have highlighted the critical importance of bleeding complications on prognosis in patients with acute coronary syndromes (ACS). In fact, the hazard for an adverse cardiovascular event associated with bleeding is similar to that of a myocardial infarction. Several bleeding risk scores are now available that reliably quantify the probability of an ACS patient experiencing a bleeding complication. Consistent and strong correlates of bleeding include older age, female sex, renal impairment, and an invasive management approach. Although patients who tend to bleed are usually more morbid compared with their non-bleeding counterparts, several lines of experimental and clinical evidence suggest an independent and causal pathway for bleeding-associated cardiovascular risk. Given the frequency and adverse prognosis associated with bleeding, interventions that might reduce such complications are now a major emphasis in the current era of ACS treatment. Recent trials have shown that several novel antithrombotics, bivalirudin and fondaparinux, reduce bleeding risk while maintaining efficacy in reducing ischemic events during ACS. Other promising strategies that continue to be tested include the use of vascular closure devices and transradial arterial access during percutaneous coronary intervention.