A rare case of CNS Burkitt's lymphoma presenting as acute Guillain-Barré syndrome is presented. A 6-year-old previously healthy female presented with acute onset of limb and truncal weakness, involvement of ocular and bulbar nerves, and areflexia. The clinical diagnosis of Guillain-Barré syndrome prompted treatment with intravenous gammaglobulin with no response. A lumbar puncture following revealed marked pleocytosis, elevated protein, and decreased glucose. Immunological, cytological, and molecular studies of these cells confirmed the diagnosis of Burkitt's lymphoma IgM, kappa with t(8;14) and rearrangement of the J and kappa immunoglobulin chains. Aggressive systemic and intrathecal chemotherapy were started and within 5 days remission was achieved. The child is in complete remission 2 years from diagnosis. Although very rare, CNS lymphoma should be taken into account in every patient presenting with the clinical features of acute polyneuropathy.