Clopidogrel is an important component of medical therapy for patients with acute coronary syndromes and those receiving coronary stents. Despite the use of clopidogrel, a significant number of patients experience recurrent adverse ischemic events. Inter-individual variability of platelet aggregation in response to clopidogrel may provide an explanation for some of these recurrent events, and small trials have linked clopidogrel resistance, as measured by platelet function tests, to adverse events. The VerifyNowTM P2Y12 assay (Accumetrics, Inc., CA, USA) is a point-of-care device that can accurately and rapidly measure the degree of platelet inhibition in patients taking clopidogrel. This assay can identify patients with a poor response to clopidogrel, and could potentially lead to change in therapy.