Objective. There is limited information regarding the long-term outcome of inflicted traumatic brain injury (TBI), including shaken infant syndrome. The purpose of this study was to describe the long-term neurologic, behavioral, and cognitive sequelae seen in this population. Methods. A cross-sectional and prospective longitudinal study was conducted of 25 children with inflicted TBI in Scotland between 1980 and 1999. After consent was obtained, neurologic and cognitive examinations were performed on all participants and sequentially in the prospective cohort. Two global outcome measures were used: Glasgow Outcome Score (GOS) and Seshia's outcome score. Cognitive outcome was assessed using the Bayley Scales of Infant Development, British Ability Scales, and the Vineland Adaptive Behavior Scales. Results. The mean length of follow-up was 59 months. A total of 68% of survivors were abnormal on follow-up, 36% had severe difficulties and were totally dependant, 16% had moderate difficulties, and 16% had mild difficulties on follow-up. A wide range of neurologic sequelae were seen, including motor deficits (60%), visual deficits (48%), epilepsy (20%), speech and language abnormalities (64%), and behavioral problems (52%). There was a wide range of cognitive abilities: the mean psychomotor index, 69.9 (SD: [+ or -] 25.73); and mean mental development index, 74.53 (SD: [+ or -] 28.55). Adaptive functioning showed a wide range of difficulties across all domains: communication domain (mean: 76.1; SD: [+ or -] 25.4), Daily living skills domain (mean: 76.9; SD: [+ or -] 24.3), and socialization domain (mean: 79.1; SD: [+ or -] 23.1). Outcome was found to correlate with the Pediatric Trauma Score and the Glasgow Coma Score but did not correlate with age at injury or mechanism of injury. Conclusions. Inflicted TBI has a very poor prognosis and correlates with severity of injury. Extended follow-up is necessary so as not to underestimate problems such as specific learning difficulties and attentional and memory problems that may become apparent only once the child is in school. Behavioral problems are present in 52% and begin to manifest clinically between the second and third years of life, although the consequences of frontal lobe injury may be underestimated unless follow-up is extended into adolescence and early adulthood. Pediatrics 2005;116:e174-e185. URL: www.pediatrics.org/ cgi/doi/10.1542/peds.2004-2739; behavior disorders/problems, head trauma, infants, neurobehavioral outcomes, shaken baby syndrome.