Gene transfer into the inner ear is an attractive technology for clinical applications. It offers the hope of preventing, arresting, reversing or curing vestibular or hearing disorders caused by hereditary diseases or environmental insults. There are currently very few treatment options for vestibular disorders and sensorineural hearing loss, and therefore, it is important to investigate and develop new technologies for inner ear disease. In utero gene transfer may indeed be an option, but this technology will have many technical and ethical issues that remain to be overcome.