A 43-year-old man with POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes), including long-standing optic disc swelling, had sudden painless vision loss in the left eye. Brain MRI revealed an intracranial mass adjacent to the left optic nerve and enhancement of the optic nerve. The mass decreased in size following chemotherapy for myeloma with some recovery of vision. This represents a unique case of optic neuropathy due to presumed plasmacytoma in osteosclerotic IgA myeloma and POEMS syndrome.