We treated a 3-year-old boy with neurofibromatosis who had an optic glioma, intraocular extension with seeding, and iris tumors. On the basis of results of ultrasonography, computed tomography, magnetic resonance imaging, and fine needle aspiration, other intraocular and orbital tumors were excluded. Because of the malignant intraocular aspect, the optic nerve glioma was extirpated. Histologic examination confirmed the diagnosis of an optic nerve glioma with intraocular extension, seeding, and iris nodules. In this juvenile pilocytic astrocytoma with secondary perineural fibrous hyperplasia, several mitoses were found in the orbital and intraocular parts. In the optic canal, three small islands were found that were compatible with the diagnosis of malignant astrocytoma, grade 3. The iris nevi appeared as iris pits and not like the Lisch nodules typical of neurofibromatosis. Café au lait spots were present on the skin. The family history was positive for neurofibromatosis. The results of this study demonstrate that optic gliomas are true astrocytomas and not hamartomas, and have a continuous scale from benign to malignant differentiation.