We report a case of cerebral dural sinus thrombosis presenting as acute subarachnoid haemorrhage and clinically mimicking an aneurysmal bleed. Awareness of this rare initial presentation of cerebral venous thrombosis is important and should be considered in the diagnostic work-up of acute subarachnoid haemorrhage. The radiologist plays a crucial role in making this often unsuspected but important diagnosis to enable prompt appropriate treatment.