Olfactory neuroblastoma (ONB) is a relatively uncommon neoplasm, and its clinicopathological presentation remains unclear. In this study, we investigated the correlation of the clinicopathological presentation with the prognosis of ONB. Twelve ONBs histologically diagnosed during the past 12 years at our university were examined. The tumors were classified in accordance with Kadish clinical staging and Hyams' histological grading. For immunohistochemical analysis, the antibodies of CXCL12, CXCR4, AE1/AE3, CAM5.2, Ber-EP4, Bcl-2, and MIB-1 were used. The patients ranged in age from 19 to 82 years old, and there were five males and seven females. Eight cases had intracranial tumor progression, which equals the advanced Kadish stage (stage C). According to histological grading, five low-grade (grades 1 and 2) and seven high-grade (grades 3 and 4) cases were included. Regarding the prognosis of ONB, a relationship was demonstrated with Hyams' grading, without Kadish staging. The MIB-1 labeling indices of Hyams' high-grade group were increased significantly compared to those of the low-grade group, and the expression level of Bcl-2 was strongly correlated with Hyams' grading. Neither of the chemokines CXCL12 and CXCR4 played a critical role as a prognostic factor, nor did any of the epithelial markers, AE1/AE3, CAM5.2, and Ber-EP4.