We describe the case of a 75-year-old woman who presented with acute loss of vision. She experienced subacute headache, hearing loss on the left side, hoarseness, and dysphagia during the previous 10 months. On admission, she had bilateral loss of vision, without any ophthalmological abnormalities, and multiple cranial nerve palsies, including left hearing loss and right IX, X, and XI nerve palsies. Head magnetic resonance imaging with contrast enhancement revealed hypertrophic pachymeningitis. Laboratory findings showed no abnormalities except for an increased sedimentation rate and increased C-reactive protein levels. A biopsy of the dura mater was performed, and histopathological analysis revealed inflammatory thickening of the dura mater with plasma cell infiltration; the infiltrating cells were immunoreactive to an anti-IgG4 antibody, thereby indicating an IgG4-related disorder. Furthermore, the histopathological analysis revealed evidence of vasculitis in both veins and arteries. After corticosteroid treatment, her visual acuity dramatically improved. Acute loss of vision with multiple cranial nerve palsies may be an uncommon presentation of IgG4-related hypertrophic pachymeningitis. However, it should be recognized that these conditions might be underdiagnosed. The possibility of central nervous system involvement in IgG4-related disorders should be considered in patients with multiple cranial nerve neuropathies associated with hypertrophic pachymeningitis, even in the absence of systemic sclerosis symptoms. In our case, early treatment with corticosteroids showed immediate effectiveness in correcting the visual symptoms.