Thanks to the advances accomplished in human genomics during the last twenty years, major progress has been made towards understanding the pathogenesis of various forms of congenital or acquired deafness. The identification of deafness genes, which are potential therapeutic targets, and generation and functional characterization of murine models for human deafness forms have advanced the knowledge of the molecular physiology of auditory sensory cells. These milestones have opened the way for the development of new therapeutic strategies, alternatives to conventional prostheses, hearing amplification for mild-to-severe hearing loss, or cochlear implantation for severe-to-profound deafness. In this review, we first summarize the progress made over the last decade in using gene therapy and antisense RNA delivery, including the development of new methods for cochlear gene transfer. We then discuss the potential of gene therapy for curing acquired or inherited deafness and the major obstacles that must be overcome before clinical application can be considered.