Because of its large spectrum of clinical manifestations, diagnosis of cerebral venous thrombosis may be very difficult. Since appropriate treatment influences prognosis, early recognition of this condition is extremely important. We report a subarachnoid hemorrhage as a rare initial manifestation of cerebral venous thrombosis. A 58-year-old woman was admitted with severe headache of sudden onset, neck stiffness, dysarthria, and ataxia. Computed tomography scan showed a subarachnoid hemorrhage in the right posterior fossa. Magnetic resonance imaging coupled with magnetic resonance angiography revealed right transverse/sigmoid sinus thrombosis with hemorrhagic infarction of the right cerebellar hemisphere leading to a pseudotumoral appearance and displacing the fourth ventricle. Anticoagulant treatment resulted in rapid clinical recovery and in resolution of the radiological signs of infarction and of the subarachnoid and subdural hemorrhages.