The height of a free fall necessary to cause injury to infants and small children is a confusing and controversial issue among health care, law enforcement, and legal professionals responsible for evaluating cases of possible child abuse. To resolve this confusion, the circumstances of falls were recorded prospectively for 398 consecutive victims of falls seen at Children's Hospital, Oakland, California. From these cases, 106 were selected for further analysis where the falls were witnessed by a second person other than the caretaker and the circumstances of the fall were documented. No injuries occurred in 15 patients, including seven falling more than 10 feet. Mild bruises, abrasions, or simple fractures occurred in 77 patients, including 43 falling more than 10 feet. Severe injuries, including intracranial hemorrhages, cerebral edema, depressed skull fractures, and compound or comminuted fractures occurred in 14 patients falling between 5 and 40 feet. However, no life-threatening injuries occurred in the 3 patients who fell less than 10 feet. These three had small, depressed skull fractures without loss of consciousness, from falling against an edged surface. Only one death occurred in this series, resulting from a fall of 70 feet. In conclusion, infants and small children are relatively resistant to injuries from free falls, and falls of less than 10 feet are unlikely to produce serious or life-threatening injury.