Summary:Vascular compression of the eighth cranial nerve is increasingly recognised as a possible cause of incapacitating audiovestibular symptoms. There have been few reports of the efficacy of surgical microvascular decompression for tinnitus, and the practise is controversial. During the last 6 years, investigation by air computed tomography (CT) cisternography initially, and fast spin-echo magnetic resonance imaging (MRI) latterly has resulted in the diagnosis of cochlear nerve vascular compression in nine patients with a primary complaint of severe tinnitus who have subsequently undergone vascular-decompression surgery. The duration of symptoms ranged between 1 and 10 years, whilst their subjective tinnitus perception varied between 30 to 60 dB above threshold. Microvascular decompression was carried out by a retrolabyrinthine approach in four and by a retrosigmoid approach in the remaining five cases, with a postoperative follow-up of 1.3 to 5 years. Tinnitus was completely abolished in three (33%), very significantly improved to a sensation level of ≤ 10 dB in four (33%), significantly improved to a level of 15 dB in one (11%), and unchanged in two (22%). Both failures had had tinnitus for 6 years and had transient abolition for 10 days after surgery. Subsequent revision decompression surgery was also unsuccessful. This small study suggests that cochleovestibular vascular compression may result in severe tinnitus, which can often be ameliorated surgically.