Otolaryngology Head and Neck Surgery is the medical and surgical specialty addressing disorders of the head and neck in both adult and pediatric populations. The goal of the encyclopedia is to serve as a single and comprehensive source of all the information that is essential for students and practitioners of the specialty. The vast amount of information included in the encyclopedia is divided into 5 volumes in line with the subspecialties of general otolaryngology, head and neck surgery, pediatric otolaryngology, otology–neurotology, and facial plastics. All volume editors are internationally recognized otolaryngologists with experience in publishing. Each section editor recruited experienced authors from all over the world to contribute on structured topics, and all entries are supported by published references. Thus, all information included in the encyclopedia is from credible sources and has been carefully screened for accuracy. The strength of the encyclopedia is its online availability and quick search features, which allow rapid retrieval of definitions and more in-depth information. Key words are hyperlinked to provide a gateway to numerous referenced manuscripts, journals, and books.