Objectives: Optic pathway/hypothalamic gliomas (OPHGs) tend to occur in young children. Treatment options consist of surgical resection, radiation therapy (RT) and chemotherapy. Due to complications induced by surgery and RT, chemotherapy has gained significant recognition for the treatment of OPHG in young children. Chemosensitivity of OPHG in very young children under 3 years of age has not been well documented. We analyzed 14 patients who were treated with chemotherapy with or without surgery. Materials and Methods: Fourteen children younger than 3 years (median age of 10 months) with OPHG were treated between 1988 and 1998. Magnetic resonance imaging was obtained in all cases. Hydrocephalus was present in 8 patients and diencephalic syndrome was noted in 6. Only 3 of these had evidence of neurofibromatosis-1. Five patients had partial tumor resection and 4 had endoscopic biopsy at the time of ventriculoperitoneal shunt placement. Pathological examination revealed low-grade astrocytoma in 5 and juvenile pilocytic astrocytoma in 4. All patients received chemotherapy: carboplatin in 8, a combination of carboplatin and vincristine in 4 and a combination of other agents in 2. Results: Eight (57%) of 14 patients had a sustained reduction of tumor during the follow-up time between 15 months and 8 years. The 5-year progression-free survival was 63%. These tumor reductions were often accompanied by clinical improvements. Diencephalic syndrome responded to chemotherapy alone in 4 of 6 patients. However, 5 others had progressive disease; 3 during the treatment and 2 following the treatment (9 months and 2 years, respectively). All these 5 patients had a partial tumor resection prior to chemotherapy. Conclusion: A majority of OPHGs responds to chemotherapy. Due to slow progression of these tumors and adverse effects of other therapeutic modalities, we recommend chemotherapy as a primary treatment for OPHGs. Our present data indicates that partial surgical resection does not enhance chemotherapy effectiveness for OPHGs in infants or children younger than 3 years.