The authors report 8 cases of youthful otosclerosis over 512 surgical otosclerosis cases. This study is compared for literature's datas: frequency comparable (1 to 1.6%), start age sometimes early, before 4 years for one case. The family's antecedents are quickly, but not always present. The clinical and audiometric study are detailed. In all cases one inner ear malformation (communication with cerebrospinal fluid) has been eliminated by one computer tomography. The treatment is often a long follow up, to operate in adolescent age, or adult. The surgery is earlier, when the hearing loss is fast. This surgery is classic and one hypertrophic stapedius platine is often found. The results are not as good as those in adults, but are correct.