Most inner ear disorders involve irreversible loss of hair cells and their associated neurons. Recent advances in genetics and cell biology have raised hopes for the regeneration or protection of these cells. Cell therapy is a rapidly growing research area, and is potentially applicable to the treatment of inner ear disorders. Recent studies on cell transplantation into the inner ear have suggested that such cell therapy may be progressing towards the clinical application. This review highlights recent advances in cell transplantation studies focusing on the inner ear.