Clopidogrel, an antiplatelet prodrug, is widely used for prevention of the recurrent cardiovascular events. CYP2C19 is one of the crucial enzymes for the activation of clopidogrel. Recent studies, mostly done in cardiovascular patients, showed association of the CYP2C19 genotypes with recurrent cardiovascular events. However, prospective data on the impact of the genetic variants in stroke patients are limited.