Neuromyelitis optica (NMO) is an inflammatory disorder of the central nervous system that predominantly affects the optic nerves and spinal cord. NMO is characterized by anti-aquaporin 4 (AQP4) antibody-mediated astrocytopathy. Recent studies have improved our knowledge of NMO. Interleukin-6 presumably plays an important role in the immunopathogenesis of NMO, because it is involved in the production of anti-AQP4 antibody in the peripheral circulation and in the enhancement of inflammation in the central nervous system. Significant advances in the understanding of the pathogenesis of NMO will help develop new treatments. The present review focuses on the current research addressing the role of interleukin-6 in NMO.