The case of a 55-year-old female is presented, in whom first a loss of the vestibular and hearing function on the left side occurred with sudden onset, and 3 days later an additional loss of functions on the right side occurred. No other neurological symptoms were present. Angiography and MRI scan revealed vertebrobasilar dolichoectasia with a thrombus attached to the wall of the basilar artery. Anticoagulative therapy improved hearing function on the right side sufficiently to allow conversation. Vestibular organs remained unresponsive to caloric irrigation. This bilateral loss of eighth nerve function is discussed as a rare case of bilateral ischemia of the labyrinthine artery due to basilar dolichoectasia.