OBJECTIVE: The goal was to use a national database to determine the incidence of abusive traumatic brain injuries (TBIs) and/or fractures and the frequency of abuse versus accidents among children <36 months of age. METHODS: We used the 2006 Kids' Inpatient Database and classified cases into 3 types of injuries, that is, (1) TBI only, (2) TBI and fracture, or (3) fracture only. Groups 2 and 3 were divided into 3 patterns, that is, (1) skull fractures, (2) skull and nonskull fractures, or (3) nonskull fractures. For each type and pattern, we compared abuse, accidental falls, other accidents, and motor vehicle accidents. RESULTS: The incidence of TBIs and/or fractures attributable to abuse was 21.9 cases per 100 000 children <36 months of age and 50.0 cases per 100 000 children <12 months of age. In the abuse group, 29.9% of children had TBIs only, 28.3% TBIs and fractures, and 41.8% fractures only. Abused children were younger and were more likely to be enrolled in Medicaid. For TBI only, falls were more common than abuse in the first 2 months of life but abuse was more common from 2 to 7 months. For TBI and skull fracture, falls were more common during the first year of life. For skull fracture only, almost all injuries were attributable to falls. CONCLUSIONS: There was overlap in TBIs and fractures attributable to abuse. Among <12-month-old children, TBIs and/or fractures attributable to abuse occurred in 1 of 2000. Falls occurred more commonly than abuse, even among very young children. Copyright © 2010 by the American Academy of Pediatrics.