The megadolichobasilar artery is a rare vascular disease, which usually becomes apparent either due to cerebral ischemia or due to compression of the brainstem or the cranial nerves, thereby leading to a large variety of neurological symptoms. We report on a patient who suffered a sudden right-sided deafness accompanied by vertigo and vomiting. Initially, an idiopathic sensorineural hearing loss was diagnosed and later on, after no improvement took place in spite of conservative therapy, a rupture of the round window membrane was suspected. Two weeks after the first symptoms had occurred the patient developed a hemiparesis on the left side.Radiology disclosed a dilated and partially thrombosed basilar artery as well as a paramedian pontine infarction. We therefore assumed that the patient's symptoms had been caused by thrombotic occlusion of the labyrinthine artery and several rami ad pontem. The article reviews the great variety of clinical symptoms caused by megadolichobasilar artery and discusses important therapeutic options.