Apathy is defined as reduced goal-directed behavior due to lack of motivation. Traumatic brain injury is a frequent cause. Drugs activating the dopaminergic system provide variable benefit. A 30-year-old patient was the victim of a severe head injury with frontal bruise at the age of 15. At the request of his family, he consulted for a 7-year history that included a lack of initiative and the inability to generate behavior spontaneously, contrasting with the ability to execute behaviors on command. He also presented indifference, major emotional disruption without sadness, pessimism, and other depressive signs. The examination found a severe apathetic syndrome confirmed by specific scales with a mild impairment of executive functions and without depressive syndrome. Encephalic MRI showed atrophy of the whole prefrontal cerebral cortex. The patient was treated with bromocriptine, which he did not tolerate, then with Selegiline at 15 mg per day, which dramatically improved his symptoms. Apathy occurs frequently after traumatic brain injury, in 23-71% of patients according to the authors. The pathophysiology of apathy has been described in anatomical terms as related to disruption of frontal-subcortical pathways. The biochemical hypothesis postulates a disruption in dopaminergic activity. The use of dopaminergic agents usually improves cases similar to our patient. Apathy is frequent following head injury, warranting a search for systematic causes. Since it increases dopaminergic activity, Selegiline is well worth trying in these patients.