Numerous biological studies have reported inter-individual variability in platelet response to clopidogrel with clinical relevance. High Post treatment platelet reactivity (ADP-induced aggregation >70%) has been proposed to define Non response to clopidogrel. We assessed in clopidogrel non responders undergoing elective percutaneous coronary intervention (PCI) the benefit of adjusted antiplatelet therapy with glycoprotein IIbIIIa (GPIIbIIIa) antagonist administration during PCI for one month clinical outcome. 149 clopidogrel non-responders referred for elective PCI were prospectively included and randomized to “conventional group” (n=75) or “active group” with GPIIbIIIa antagonist (n=74). All patients received 250 mg aspirin and 600 mg clopidogrel before PCI and platelet testing. The rate of CV events at one month was significantly lower in the “active group” than in the “conventional group”: 19% (n=14) vs. 40% (n=30), p=0.006, [OR (95%CI): 2.8(1.4-6.0)]. No patient in either group had post procedural TIMI major bleeding or required transfusions. The present study suggested benefit of tailored antiplatelet therapy during elective PCI with GPIIbIIIa antagonist for clopidogrel non responders without increased bleeding risk.