For most medical examiner departments, approximately 10 percent of the decedents brought to the department are unidentified due primarily to skeletonization, decomposition, severe burning/charring, or trauma that destroys head and facial features. When presented with unidentified remains, the medical examiner must first determine whether the remains are human. Procedures for doing this are described. The identification of an unknown decedent begins at the scene where the body is found and proceeds forward and backward based on evidence collected from the scene. The following records may contain information for comparison with identifying features developed by physical examination and forensic science analyses: missing persons reports, fingerprints, medical records, dental records, radiographs, photographs, employment records, police records, passports, and school records. Identification methods described are visual recognition by persons who knew the decedent, distinctive clothing worn by the decedent, fingerprints and footprints, comparison of the decedent's fingerprints with those contained in automated fingerprint identification systems, dental examination and comparison, and radiographic examination and comparison. A separate section of the chapter focuses on identification when only skeletal remains are found. Issues addressed are determination of sex, age, race, height, and eye and hair color. A discussion of identification of remains in the course of an autopsy examination considers birthmarks, congenital defects, tattoos, and scars; the identification of distinguishing diseases; and toxicology examinations that can provide information on lifestyle and mental and physical health. The chapter concludes with a discussion of DNA analysis and comparison through a hair examination. 42 figures, 2 tables, and 45 references