This report describes a 72-year-old woman presenting MPO-ANCA-associated hypertrophic pachymeningitis and venous thrombosis. Five years prior, positive MPO-ANCA and renal dysfunction had been indicated. At that time, oral steroids and tacrolimus were given to treat systemic vasculitis. During the course of the disease, she repeated otitis media. Saddle nose appeared. She was suspected of having localized type granulomatosis with polyangiitis (GPA). She was hospitalized because of consciousness disturbance and was diagnosed as having MPO-ANCA-associated hypertrophic pachymenigitis and venous thrombosis. Brain MRI detected thick dura mater with abnormal enhancement, predominantly on the right cerebral hemisphere, and tentorium cerebella partially along with the cerebral sulci. MRI revealed vasogenic brain edema lesions in the right occipital, parietal, and temporal lobes and cytotoxic edema lesions in the right parietal lobe and centrum semiovale. MR venography revealed stenosis of the venous sinus including confluence of sinuses, straight sinus, and right transverse sinus. Subsequent treatment with corticosteroids, an immunosuppressant, and an anticoagulant led to recovery. No patient with MPO-ANCA-associated hypertrophic pachymenigitis and venous thrombosis that developed alternation of consciousness has ever been reported. This is therefore regarded as a rare case.