There have been several case reports of acute ophthalmoparesis without ataxia subsequent to infection or immunization. The nosological position and therapy for acute ophthalmoparesis have yet to be established. Sera from patients are reported to have IgG anti-GQ1b antibody, which is frequently found in sera from patients with Fisher's syndrome. To establish the etiology of acute ophthalmoparesis, I tested sera from 8 patients with acute ophthalmoparesis for anti-GQ1b antibody. High IgG anti-GQ1b antibody titers were present in sera from patients in the acute phase of the illness. I describe the successful treatment with plasmapheresis and intravenous immunoglobulin. Some cases of acute ophthalmoparesis following infection or immunization may be categorized as an auto-immune disease related to Fisher's syndrome.