The presented article shows the current scientific concept including diagnostics and therapy of otosclerosis with an emphasis on surgical treatment options. The three main proposed causes for otosclerosis are viral and hormonal origin as well as a genetic predisposition. In 25 to 50% a familiar accumulation can be seen. Usually patients become aware of clinical problems by a progressive middle ear hearing loss in the young adulthood. In up to 80% of cases both ear become affected during lifetime. Surgical options of therapy are the stapedotomy, stapedectomy and the laser-assisted stapedotomy. In every case the alternative use of a hearing aid must be offered during the consultation. Typical surgical complications are rare but can be persistent vertigo, secondary facial palsy and a sensorineural hearing loss up to complete single-sided deafness in up to 1% of the cases. The most common finding which necessitates stapes revision surgery is the necrosis of the long incus process with dislocation of the stapes piston.