Osteopontin (OPN) is a cytokine that involves in vascular remodeling processes in cerebrovascular diseases. The association of its gene with ischemic stroke was investigated in a Korean population. Representative sequence variants covering the entire OPN gene were genotyped in 455 controls and 271 patients with ischemic stroke including large artery atherosclerosis (LAA), small vessel occlusion, and cardioembolism. Analysis with the individual tagging variants and their haplotypes revealed an evidence of association only with LAA. Significances were shown with the haplotypes, especially with the TCA at the loci C2140T, C5891T, and A7385G conferring a risk of 2.09 for LAA (P < 0.05). The CG at the loci C1013T and A7385G was the most protective haplotype (OR = 0.66, P < 0.05). Our findings suggested that several haplotypes of OPN gene contributed to determining risk factors as well as protective factors of LAA.