Craniofacial microsomia is the second most common congenital syndrome of the head and neck. Presenting as hypoplasia in any of the structures of the first and second branchial arches, hemifacial microsomia is classically typified by the OMENS + criteria, which is described in detail below. Management involves a multidisciplinary effort addressing any hearing deficits as well as surgical procedures to reconstruct hypoplastic facial structures including the mandible, ear, and overlying soft tissues.