The Sudden Infant Death Syndrome (SIDS) is 'the sudden death of an infant under one year of age which remains unexplained after the performance of a complete postmortem investigation, including an autopsy, an examination of the scene of death, and review of the case history.' In the United States alone, SIDS accounts for over 7,000 deaths a year. This Atlas, based on a prospective study of over 750 SIDS cases with an equal number of age and birth weight matched controls, has been compiled as a handbook or work manual for practitioners of general and forensic pathology. In addition to a detailed discussion of autopsy techniques and a description of the 'classic' or typical pathology associated with SIDS, the Atlas presents a broad overview of the normal histology of the infant in the postneonatal period. Other causes of sudden death in infants are described and illustrated along with incidental or inconsequential lesions seen in SIDS cases. Individual cases of SIDS and various explained deaths in infants are presented in some detail. Appendices include examples of a standard autopsy protocol as well as sample letters that may be used in contacting the parents and grandparents of a SIDS infant to inform them of the results of the postmortem examination. This Atlas will be useful to pathologists and other physicians as well as health care professionals who are called upon to diagnose infants who may have died of the Sudden Infant Death Syndrome.