Central nervous system involvement in primary Sjögren's syndrome (pSS) is less common and usually presents as white matter lesions, neuromyelitis optica spectrum disorder (NMOSD), or transverse myelitis. NMOSD is an immune-mediated inflammatory demyelinating disease of the central nervous system with a high rate of relapse and significant disability. Studies have shown that patients with pSS combined with NMOSD have more severe symptoms and poorer prognosis. Here, we present a case of critical illness in pregnancy-associated NMOSD combined with Sjögren's syndrome. The patient was a 30-year-old pregnant woman with a history of Sjögren's syndrome who was diagnosed with NMOSD. She received combination therapy with steroids, intravenous immunoglobulin (IVIG), and hydroxychloroquine during pregnancy, resulting in partial resolution of numbness below the waist. However, due to irregular medication adherence outside the hospital setting, she developed weakness in her right lower limb accompanied by inability to move it, while her left lower limb still had some mobility but occasional numbness along with urinary and fecal incontinence. Ten days later, she was admitted to the emergency department where an emergency cesarean section was performed to deliver a healthy baby boy. However, her condition worsened postpartum as she developed high fever accompanied by bilateral lower limb paralysis and weakness along with loss of voluntary control over urination and defecation. The patient underwent ano-ther course of treatment consisting of steroids and IVIG; however there was limited improvement in symptoms observed after this intervention. Following administration of rituximab for the first time, the patient developed urinary tract infection which was successfully managed before continuing regular infusions. In later stages the patient could walk slightly with a limp and regained control over urination and defecation, allowing her to resume normal activities. This case suggests that combination therapy with steroids, IVIG, and hydroxychloroquine should be considered for the patients with pregnancy-associated NMOSD combined with Sjögren's syndrome. Rituximab can significantly improve symptoms such as postpartum paralysis in patients with NMOSD, however, there may be a risk of infection associated with its use.