Coexistence of the neuromyelitis optic spectrum disorder and SS.A 37-year-old woman with a history of bilateral optic neuritis presented with paraparesis. Her spinal MRI showed LETM and she was positive for AQP4-Ab. Meanwhile, she also had SS, according to the symptoms (dry eye and mouth), signs (positive scintigraphy and Shirmer’s test), histopathology (lymphocytic infiltration in the salivary gland biopsy), and a positive anti-Ro antibody result. She had NMOSD-AQP4 and SS.AQP4-Ab, autoantibody against aquaporin-4; LETM, longitudinally extensive transverse myelitis; NMOSD-AQP4, neuromyelitis optica spectrum disorder with AQP4-Ab; SS, Sjogren’s syndrome.