Critical factors affecting traumatic brain injury (TBI) outcome in children and adolescents are explored with an emphasis on an examination of age at injury as a predictor of memory functioning. Age at injury and other injury-related and demographic predictors (i.e., severity, time postinjury, gender, and socioeconomic status [SES]) of memory and achievement outcome were examined in 65 children and adolescents post-TBI compared to 65 age-matched noninjured controls. Although robust findings have been found for age at injury as a general predictor of outcome, age was not found to be a significant predictor of memory functioning following pediatric TBI. Structural equation modeling suggests that the most parsimonious model of post-TBI outcome contains two causally related latent variables: one defined by gender, SES, injury severity, and age at injury, and one defined by general cognitive functioning.