The definition of what constitutes child abuse has changed dramatically in the past 25 years. Although the battered child syndrome model appears to prevail, other professionals, caregiving institutions, and government agencies have defined the problem more expansively. A more embracing medical concept of child abuse, which goes beyond the victim-perpetrator model and the need to assign blame, draws attention to the relationships among pediatric social illnesses, unintentional injuries, poisonings, and a condition known as failure to thrive. Recent attention has also been drawn to two entities of particular concern to physicians and other medical workers, the Munchausen syndrome by proxy and the problem of child sexual victimization by professionals. Sources of data on child abuse are noted, along with costs and outcomes of child abuse. The importance of appropriate interventions and preventive efforts is stressed from both theoretical and practical perspectives. 114 references