Magnetic resonance (MR) images of 62 patients with tinnitus were reviewed. These included T1-weighted and T2-weighted axial images and three-dimensional spoiled gradient-recalled acquisition in steady-state (3D-SPGR) imaging with gadopentetate dimeglumine. In 49 cases with tinnitus occurring gradually, the MR images of 2 cases (4.1%) suggested arterial dissection of the vertebrobasilar system. One of these patients underwent vertebral angiography (VAG) and no dissection was confirmed. In 13 cases of sudden-onset tinnitus, MR images of 3 cases (23.1%) suggested arterial dissection. Of these three cases, VAG was performed in two, resulting in arterial dissections being confirmed in two cases. It was concluded that the arterial dissection of the vertebrobasilar system was one of the causes of sudden-onset tinnitus. Abnormalities in neurotological examinations in cases with tinnitus caused by the arterial dissection of vertebrobasilar system implied that the tinnitus was caused by inner ear dysfunction.