Myelin oligodendrocyte glycoprotein (MOG)-IgG detected by the cell-based assay is associated with demyelinating diseases of the central nervous system, such as optic neuritis, myelitis, and acute disseminated encephalomyelitis, but rarely with peripheral neuropathy. Here, we describe the case of a 32-year-old MOG-IgG + woman who developed central and peripheral demyelinating lesions. In contrast to previous similar cases, she uniquely presented with repeated subsequent relapses in the peripheral nerve, mimicking chronic inflammatory demyelinating polyneuropathy. Possible pathogenic implications of MOG-IgG in combined central and peripheral nervous system diseases are considered.