OBJECTIVE. The goal was to assess the proportion of children with fractures attributable to abuse and the incidence of fractures caused by abuse among children < 36 months of age who were hospitalized in the United States. METHODS. We used the Kids' Inpatient Database, which has discharge data on 80% of acute pediatric hospitalizations in the United States, for 3 time periods (1997, 2000, and 2003). Fractures attributable to abuse in children < 36 months of age were identified by both an International Classification of Diseases, Ninth Revision, Clinical Modification code for fracture and a diagnosis external-cause-of-injury code for abuse. Weighted estimates of the incidence were calculated. RESULTS. Among children < 36 months of age who were hospitalized with fractures, the proportions of cases attributable to abuse were 11.9% in 1997, 11.9% in 2000, and 12.1% in 2003. The proportions of cases attributable to abuse decreased with increasing age;for example, in 2003, the proportions attributable to abuse were 24.9% for children < 12 months of age, 7.2% for children 12 to 23 months of age, and 2.9% for children 24 to 35 months of age. In 2003, the incidence of fractures caused by abuse was 15.3 cases per 100 000 children < 36 months of age. The incidence was 36.1 cases per 100 000 among children < 12 months of age; this decreased to 4.8 cases per 100 000 among 12- to 23-month-old children and 4.8 cases per 100 000 among 24- to 35-month-old children. CONCLUSIONS.The Kids' Inpatient Database can be used to provide reasonable estimates of the incidence of hospitalization with fractures attributable to child abuse. For children < 12 months of age, the incidence was 36.1 cases per 100 000, a rate similar to that of inflicted traumatic brain injury (25-32 cases per 100 000). Copyright © 2008 by the American Academy of Pediatrics.