We report two unusual cases of delayed hearing loss after microvascular decompression (MVD) for hemifacial spasm. In the first case, A 59-year-old female noted left hearing loss one week after receiving MVD for left hemifacial spasm. In the second case, A 39-year-old male also noticed ipsilateral hearing loss on the 7th day after MVD for right hemifacial spasm. Both cases were treated by steroid. Two months after the onset, their hearing function improved dramatically. These cases indicated that the delayed hearing loss after MVD for hemifacial spasm can occur, even when gentle microsurgical technique is used, but the prognosis for this condition is fairly good.