Background: Neuromyelitis Optica (NMO) is an autoimmune inflammation of the central nervous system in which autoantibodies are released against Aquaporin-4 (AQP-4), astrocytic water channels. The disease is characterized by transverse myelitis and optic neuritis. Viruses could be inflammatory agents in the brain. Due to such inflammatory reactions, autoantibodies would cross the blood brain barrier. Therefore, recognizing the responsible viral agent may help us prevent or treat NMO. 
Objectives: To investigate the probable association between Cytomegalovirus infection (CMV) and Neuromyelitis Optica.
Materials & Methods: This descriptive study was performed on 25 patients with NMO, 30 patients with Multiple Sclerosis (MS) referring to an academic MS Clinic and 30 healthy individuals in Isfahan City, Iran in 2016. In order to detect DNA of CMV in the sera of the studied groups, real-time PCR technique was used with hydrolyzing probes such as TaqMan. Beacon Designer 7 was used to design a primer and probe. The Chi-square test was used for statistical analysis in SPSS 16. 
Results: Three study groups had no significant difference in terms of age (P=0.33) and gender (P=0.599). All of the samples were negative for CMV DNA. There was no significant difference between three groups of study (P=0.33).
Conclusion: Regarding the negative real-time PCR results of all samples, and especially using higher specificity of primers and probes in detecting this virus, it can be inferred that no significant correlation exists between CMV infection and NMO disease.