Here, we describe neuroimaging findings of an unusual case of severe vertebrobasilar dolichoectasia producing obstructive hydrocephalus. CT and MRI performed in a 71-year-old woman presenting with clinical features of raised intracranial pressure revealed severely ectatic and tortuous vertebral and basilar arteries. The ectatic basilar artery was causing compression and flattening of the midbrain. This had resulted in aqueductal compression and consequent obstructive hydrocephalus. The patient underwent emergency ventricular drainage, with resulting decompression of the ventricles and resolution of symptoms. Vertebrobasilar dolichoectasia refers to a markedly dilated and tortuous vertebrobasilar arterial system, occasionally presenting with thomboembolic episodes or symptoms related to local compressive effects, such as cranial nerve palsies. Direct midbrain compression with obstructive hydrocephalus is a rare complication that mandates emergency ventricular decompression.