We reviewed the charts of 21 children admitted to the hospital with rib fractures to determine the cause of trauma, the relationship of the number and location of rib fractures to other injuries, the course of flail chest in children, and the frequency and characteristics of injuries caused by child abuse. Sixteen (76%) of 21 children were injured by accidental causes, most commonly by motor vehicles. However, five (24%) children were victims of child abuse. Nineteen children fractured an average of 3.5 ribs (range 1 to 8), while two other children fractured 22 and 23 ribs. Neither an increased number of fractures, nor first or second rib fractures were associated with more severe intrathoracic injuries. Two children with flail chest required intubation but recovered without further complications. The five children with nonaccidental rib fractures were young, had an unexplained history, and a paucity of multiple trauma. These characteristics should alert the physician to the possibility of child abuse in the patient with rib fractures.