Introduction: Neuromyelitis optica spectrum disorders (NMOSD) is an autoimmune, inflammatory disease of the central nervous system affecting the optic nerves and spinal cord. Most NMOSD patients have autoantibodies against the astrocyte water channel protein aquaporin-4 (AQP4). Eculizumab treatment is used effectively and safely in AQP4-IgG+ NMOSD. Our study evaluated the prognosis and outcomes of all clinical trial (PREVENT) patients from Turkey who received eculizumab treatment for AQP4-IgG+ NMOSD. Method: Clinical and demographic data of all patients enrolled in the PREVENT and OLE clinical trial in Turkey were analyzed during the study period and after the study ended. Clinical follow-up results were recorded in detail in patients who had to discontinue eculizumab treatment. Results: The study included 10 patients who participated in PREVENT and OLE. Seven patients completed the studies, three patients did not continue the study and were switched to other treatments. Only one of the seven patients was able to continue treatment after eculizumab was approved in AQP4-IgG+NMOSD. The other six patients could not continue treatment due to reimbursement conditions. Four of the six patients who could not continue eculizumab treatment experienced early relapse (within the first three months after stopping the drug). All of these patients had high disease activity before eculizumab and had never relapsed under eculizumab treatment over the long term. Conclusion: Eculizumab was used effectively and safely in Turkish AQP4-IgG+NMOSD patients with high disease activity. Disease reactivation and relapse may occur after discontinuation of eculizumab treatment in patients with a long-term stable course. In these cases, close monitoring for disease reactivation is recommended.