Traumatic brain injury (TBI) is a very usual event, associated with very high morbidity¿s rate. Moreover, the mild TBI consume a lot of resources, both human and financial. The target of this study was to describe a large series of adult patients suffering mild TBI, treated at the University Hospital of Getafe, between 2010 and 2015 (n = 2480), studying the epidemiological profile and analyzing the diagnosis and treatment, to establish the main prognostic factors that influence the final result. We performed a retrospective study, reviewing medical history. Mild TBI is more common in men, and the most common causative mechanism is the traffic accident, in our region. We propose a model for classifying patients according to risk groups, which divided them into low, intermediate or high risk, which correlates well with the final result. We study the indication of skull radiography and computed tomography (CT), as well as hospital admission for clinical observation. In this study, the presence of neurological focus on clinical examination, the existence of fracture on plain radiographs, the age and the coagulation disorders are associated with increased likelihood.