From 1991 to 1995, we reviewed the medical records of 200 pediatric patients with systemic malignancies to study the occurrence of neurologic complications and their treatment. A total of 25 patients with neurologic complications were found. Complications included intracranial metastasis (one patient), intraspinal metastasis (one), spinal epidural compressions (three), leptomeningeal metastases (six), metabolic encephalopathy (10), opportunistic infection (one), cerebrovascular disorders (three), treatment complications (six) and paraneoplastic syndromes (two). Ten patients had seizures. One patient with acute lymphoblastic leukemia (ALL) had the unusual complication of cytomegalovirus retinitis and glaucoma. Seven patients had neurologic features at presentation. ALL was the most common malignancy (56%) and neuroblastoma (20%) was the second. Neurologic deficits are frequently seen in pediatric patients with systemic malignancies and can, in fact, be the presenting signs. Early diagnosis and treatment is important to prevent further neurologic disability.