Meningioma and glioma represent two common primary intracranial tumors. However, the coexistence of these two lesions in the same patient at the same location is rare. Here, we present a case of a fibroblastic meningioma with a secondary glioblastoma occurring at the same location. A 67-year-old woman underwent surgery for a left frontal parasagittal meningioma, and the tumor was subtotally removed. Two years and 11 months after the surgery, the patient had a tumor at the same location with invasion into the adjacent brain, suggesting recurrent meningioma with malignant transformation. The resected tumor was confirmed histopathologically as a glioblastoma. Genetic analysis revealed that the isocitrate dehydrogenase 1 and 2 genes were wild type, and the TERT promoter mutation was detected. The gene analysis suggests that the tumor was a de novo glioblastoma, not a secondary glioblastoma from a lower-grade glioma. (Received April 9, 2020; Accepted May 27, 2020; Published October 1, 2020).