A 50-year-old man developed cauda equina syndrome of unknown etiology that was stable for 20 months. Two months prior to sudden death, he experienced new back pain, confusion, seizures, and multiple cranial nerve palsies. Neuropathologic examination revealed angiotropic lymphoma without parenchymal involvement or infarcts in the brain, spinal cord, and muscle. In addition, nerve roots in the cauda equina contained angiotropic lymphoma and infarcts of various ages. Angiotropic lymphoma should be considered as a cause of cauda equina syndrome and of disorders that affect the central and peripheral nervous systems concurrently.