A 6-year-old girl presented with visual deterioration that had progressively worsened over 2 months. MR imaging revealed a sellar, para- and suprasellar lesion. Subtotal tumor resection was performed. Histopathological diagnosis was glioblastoma of the optic chiasma. Chiasmatic glioblastoma is rare in adults and extremely uncommon in children. Surgical resection implies a risk of severe endocrinologic and opthalmologic complications.