We report a rare case of a central nervous system collision tumor in a 40-year-old woman. Histopathological examination of her large temporal tumor revealed two different components making up the tumor tissue. The predominant component of the tumor was found to be a primitive neuroectodermal tumor. The other component was glioblastoma multiforme. Both of these tumors carry a poor prognosis, and primitive neuroectodermal tumors are extremely uncommon in adults. Central nervous system neoplasms with the combined features of both primitive neuroectodermal tumor and malignant glioma are very rare and represent a diagnostic and treatment predicament. The patient underwent surgical resection, radiation therapy, and chemotherapy targeting both the primitive neuroectodermal tumor and glioblastoma. Our patient has been fortunate in not showing any sign of recurrence and will celebrate the third anniversary since her diagnosis this January.