Many children suffer an injury to the head at some time, but relatively few of these cause major problems. However, in a few cases the sequelae can be far reaching. This review considers how to evaluate the significance of a head injury. Factors to consider are (1) injury variables: cause, severity and type of injury; (2) child variables: premorbid functioning, age, and developmental level of the child both at injury and at assessment; and (3) the cognitive, behavioural, and emotional problems that may arise. Parental beliefs and knowledge about the injury as well as the overall effect of an injury on the family as a whole are also considered.