Abusive head injuries are among the most common causes of serious and lethal injuries in children. These injuries may result from impact or shaking or a combination of these mechanisms. These mechanisms cause the child's head to undergo acceleration-deceleration movements which may create inertial movement of the brain within the cranial compartment. Differential movement between the brain and skull may result in subdural and subarachnoid hemorrhages and traumatic diffuse axonal injury. This paper will discuss the unique anatomical and developmental features of the immature brain, skull, and neck which render young children particularly vulnerable to shearing injuries, the pathology of those injuries, and the mechanisms of these injuries.