Pilomyxoid astrocytoma (PMA), a recently described variant of low-grade astrocytoma is associated with a high rate of recurrence and a propensity for CSF seeding. While cases of PMA have been reported in infants and young children, there has been no report of PMA in patients with neurofibromatosis. The first reportable case of PMA occurring in a child with neurofibromatosis type 1 (NF1) is described. Following presentation with obstructive hydrocephalus, the patient underwent a partial resection of a third ventricular tumor. Histology confirmed the typical features of PMA. The patient demonstrated a partial response to chemotherapy. The authors review the literature on PMA and discuss the specific issues associated with this diagnosis in the context of a child with neurofibromatosis.