Diffuse axonal injury (DAI) is a microscopic damage of axons in the brain. Its occurrence results from head trauma with acceleration or deceleration. This article presents current knowledge about DAI and two cases of patients who experienced DAI as a consequence of a traffic accident. A26 years old man was brought to hospital after traffic accident during which his vehicle had overturned. Computed tomography (CT) showed features of brain edema and disseminated small petechiae. Psychiatric consultation on ninth day of hospitalization showed memory deficits presenting as retrograde and anterograde amnesia, attention deficits and lack of criticism in regard to his condition. A 38 years old woman who was hit by a car while cycling was admitted to hospital. CT scan showed features of brain edema, subarachnoid hemorrhage and multiple fractures. On the tenth day of hospitalization the patient was confused, did not remember new information, her psychomotor drive was increased and she presented lack of criticism in regard to her condition. While suspecting DAI we should be vigilant, particularly in cases of patients hospitalized due to traffic accidents with behavioral problems, features of amnestic syndrome and without significant focal neurological symptoms.