A 45-year-old man visited with suboccipital and posterior neck pain accompanied with blurred vision, dysarthria and paralytic feeling for 7 months. Magnetic resonance imaging revealed large eccentrically located cyst (6×4.8 cm) within posterior fossa which compressed right side cerebellar hemisphere and brainstem. The transparent cyst wall and fluid were removed by suboccipital craniectomy and the symptoms disappeared. Western blotting of the patient's cyst fluid reacted positively with the anti-cysticercus 150 kDa antibody and therefore the giant cyst was proved to be unusual giant neurocysticercus.