Traumatic brain injury (TBI) is a common and potentially devastating problem. The classification of TBI is necessary for accurate diagnosis and the prediction of outcomes. The increased use of early sedation, intubation and ventilation in more severely injured patients has decreased the value of the Glasgow Coma Scale for the purposes of classification. An alternative is the classification of TBI according to morphological criteria based on computed tomography (CT) investigations. This article reviews the current classification and prediction of outcomes in TBI based on CT imaging. Classifications based on the presence or absence of intracranial local lesions, diffuse injury, signs of subarachnoid or intra-ventricular haemorrhage and fractures or foreign bodies are considered, and their predictive value is discussed. Future studies should address the complicated issue of how optimally to combine CT characteristics for prognostic purposes and how to improve on currently used CT classifications to predict outcomes more accurately.