In 1989 the International Standards Organization (ISO) adopted terms intended for descriptive use in prosthetics, orthotics and related allied health professions. Included are ISO Standard 8548-1, Prosthetics and Orthotics—Limb Deficiencies, Part 1: Method of Describing Limb Deficiencies Present at Birth; and Standard 8549-1, 2 & 3, Prosthetics and Orthotics—Vocabulary, Part 1: General Terms for External Limb Prostheses and External Orthoses, Part 2: Terms Relating to External Limb Prostheses and Wearers of these Prostheses, and Part 3: Terms Relating to External OrthosesIn 1993, the American Academy of Orthotists and Prosthetists (AAOP) and the American Orthotic and Prosthetic Association (AOPA) adopted and endorsed the ISO terminology. This terminology is also supported and endorsed by the American Academy of Orthopaedic Surgeons (AAOS) and the International Society for Prosthetics and Orthotics (ISPO). This article reviews some of the ISO terms