BACKGROUND: Hypotension frequently occurs in patients who are undergoing plasma exchange procedures. However, the prevalence, clinical manifestations, and determinants of hypotension during plasma exchange in patients with neuroimmunological disorders have not been fully elucidated. The aim of this retrospective cohort study was to evaluate the current status and influencing factors of hypotension during plasma exchange in patients with neuroimmunological diseases, to provide insights for clinical care. METHODS: This study encompasses patients diagnosed with neuroimmunological disorders who received plasma exchange treatment at a tertiary hospital in Nanjing, China, over a period from February 1, 2023, to April 30, 2024. The demographic characteristics and clinical profiles of these patients were subjected to a comprehensive analysis. To ascertain the factors influencing the development of hypotension during plasma exchange, a logistic regression analysis was performed. RESULTS: A total of 206 patients with neuroimmunological diseases were included, the incidence of hypotension during plasma exchange in patients with neuroimmunological diseases was 33.01% (68/206). There were statistical differences in the age, use of sedative drugs during plasma exchange, pre-plasma exchange systolic blood pressure and serum calcium between hypotension and control group. Logistic regression analysis indicated that age [odds ratio (OR) =2.851, 95% confidence interval (CI): 1.978-3.194], use of sedative drugs during plasma exchange (OR =3.175, 95% CI: 2.363-4.425), pre-plasma exchange systolic blood pressure (OR =0.857, 95% CI: 0.410-0.932), and serum calcium (OR =0.791, 95% CI: 0.340-0.895) were the influencing factors of hypotension during plasma exchange in patients with neuroimmune diseases. CONCLUSIONS: The incidence of hypotension during plasma exchange in patients with neuroimmune diseases is relatively high. Health care providers should actively take measures against factors associated with hypotension to reduce its occurrence during plasma exchange.