The incidence of early stent thrombosis is decreasing because of the development of new generation drug-eluting stents (DES) and dual antiplatelet therapy. However, early stent thromboses still occur with fatal complications. Nowadays, investigations are focusing on the hyporesponsiveness of clopidogrel and CYP2C19 genetic correlation to reveal the cause of early stent thrombosis. Herein, we report a case of simultaneous early triple stent thrombosis related with clopidogrel resistance and CYP2C19 genetic mutation.