Background: Acute disseminated encephalomyelitis (ADEM), possibly demyelinating is an acute, rapidly progressive autoimmune process characterized by CNS demyelination (frequently associated with involvement of optic nerves) due to immune-mediated inflammation, which requires rapid diagnosis and selection of appropriate early treatment. The aim of the study was to present an unusual case of ADEM with bilateral involvement of optic nerves. Material and methods: A case study presentation. Results: Case report study of a 47-year-old man presented with progressive loss of vision in both eyes, numbness in the upper and lower limbs, static and gait disorders, urinary retention. The clinical onset was preceded by a Covid-19 infection 3 weeks before presentation. ENG demonstrated sensitive axonal polyneuropathy, brain MRI – demyelination in left frontal lobe area; cervical and thoracic contrast MRI – without pathological changes, visual evoked potentials results suggestive of prechiasmic demyelinating involvement on the right side, lumbar puncture – impossible to perform, ophthalmological examination – neuroophthalmopathy of unknown etiology, anti-MOG, anti-AQP4 antibodies – negative. Progressive evolution of the disease, following the first-line treatment (Prednizolon 500 mg, N8) and plasmapheresis. Home discharge with second-line treatment with Azathioprine 50 mg without positive dynamics. Conclusions: The presented case of ADEM proved no therapeutic effects to plasmapheresis and immunosuppressive treatment in spite of its autoimmune pathogenesis. Other therapy options to be considered: mofetil mycophenolate, IV IG, calcineurin inhibitors or other immunomodulatory agents.