This article reviews an emergent area of traumatic brain injury (TBI) literature; namely, developmental outcomes of TBI sustained during the early childhood and preschool period. The developmental time period from birth through age 5 years is one of significant growth and maturity, particularly in the neurological development of the child. An injury to the brain can compromise the neurological integrity of the brain and can disrupt subsequent development and associated functions. A TBI may significantly impact how the child learns core academic skills, interacts with peers, expresses wishes, wants, and emotions, and may shape his or her role in the family. In addition to reviewing this important emergent area, this article addresses the available literature on the epidemiology of TBI in the preschool years, causes and neuropathological mechanisms, functional outcomes, and selected factors that affect outcomes. The review concludes with a listing of implications for the early childhood special educator.