Recent studies of outcome after traumatic brain injury (TBI) emphasize the adverse effect of diffuse brain injury on linguistic development. This article reviews studies of lexical development, discourse processes, and reading in children and adolescents with TBI. The child's developmental level at the time of injury is related to the pattern of deficits. Young children who sustain severe TBI are particularly vulnerable to linguistic deficits at both lexical and discourse levels. TBI in older children and adolescents preferentially disrupts higher-order discourse functions. The contribution of deficits in fundamental processes, such as working memory and processing speed, to linguistic outcomes requires further investigation.