A right-handed woman with no personal or family history of psychosis suffered from simple partial sensory seizures involving the left extremities with frequent secondarily generalized tonic–clonic seizures since the age of 35. She was diagnosed with a right-parasagittal parietal meningioma, and subsequently underwent surgery, which resulted in seizure frequency-reduction >90%. Six years later, at the age of 41, the neurological condition of the patient deteriorated, with significant increase in seizure frequency, and development of left hemiparesis and schizophrenia-like psychosis. Brain MRI revealed recurrence of a large meningioma, and another surgery was performed. After surgery, the patient became seizure-free. The psychotic symptoms were characterized by severe paranoid delusions of persecution and reference related to her neighbors and family members, and auditory hallucinations, to a lesser extent. Schizoaffective disorder and mood disorder (e.g., major depression) with psychotic features were ruled out. After initiation of treatment with antipsychotics (i.e., risperidone), the psychotic symptoms showed gradual improvement. Postoperative magnetoencephalography showed no epileptic discharge but prominent delta/theta activity surrounding the tumor, likely representing perilesional edema and dysfunctional cortex.