In order to clarify the role of arteriosclerosis in the development of and recovery from sudden deafness, we evaluated arteriosclerosis in patients with sudden deafness, using pulse wave velocity (PWV) as a marker. Arteriosclerosis was observed in 69% of the sudden deafness patients and the initial hearing level in the patients with arteriosclerosis was worse than those without arteriosclerosis. After treatment with a steroid and lipid microsphere-incorporated prostaglandin E₁ (lipo-PGE₁), the recovery rate of the patients with arteriosclerosis was significantly lower than those without arteriosclerosis. These findings suggest that arteriosclerosis is an exacerbating condition and a poor prognostic factor in patients with sudden deafness. On the other hand, PWV in the patients with arteriosclerosis who recovered tended to decrease after the treatment, suggesting that the circulation-improving effect of lipo-PGE₁ may contribute to the recovery of the hearing loss related to arteriosclerosis.