Antithrombotic therapy is imperative in the management of patients presenting with an acute coronary syndrome (ACS). The combination of antiplatelet therapy in conjunction with antithrombotic therapy has become the standard of care in improving the morbidity and mortality of patients with an ACS and in reducing ischemic complications of percutaneous coronary intervention. Patients with an ACS are at increased risk for a recurrent event, both in-hospital and for several months afterward. Secondary prevention to reduce these events is accomplished through the establishment of appropriate medical therapy. Dual antiplatelet therapy with aspirin and adenosine 5'-diphosphate P2Y(12) receptor blockers such as ticlopidine or clopidogrel are integral components of this regimen; however, both of these thienopyridines have a relatively slow onset of action and variable bioavailability. Prasugrel, a third-generation thienopyridine approved by the US FDA in 2009, has a more rapid onset of platelet inhibition than clopidogrel and ticlopidine because of increased efficiency of prodrug-to-active metabolite conversion. The result is higher and less variable concentration of the active metabolite within 60 minutes following oral dosing. Phase II and III trials assessing the safety and efficacy of prasugrel have been completed, including JUMBO-TIMI 26, PRINCIPLE-TIMI 44, and TRITON-TIMI 38. These trials demonstrated greater inhibition of platelet aggregation and lower rates of the composite endpoint of death, non-fatal myocardial infarction, and stroke compared with clopidogrel. However, major bleeding occurred more frequently with prasugrel treatment than with clopidogrel. This review highlights the current state of evidence-based antiplatelet therapy and provides guidance on appropriate use of prasugrel in cardiovascular medicine.