Introduction: Cranial wounds encephalic penetrating by stab are rare and repesent 0.4% of Head trauma. They are often observed in an attempt at autolysis in mentally ill people, or in physical aggression. We report here a case of an adolescent victim of attack by the penetration of a knife into his brain. Patient and method: This is a patient aged 17 years old, with no known medical history, admitted to the Emergency Reception Department of the Gabriel TOURE University Hospital for open head trauma following a physical attack with the penetration of a knife inside his headrane. The entire blade of the weapon was lodged in his brain parenchyma. The entry point was the right parietal bone. The patient had a Glasgow score of 15/15, with good hemodynamic status. The cranial scanner encephalic which was carried out a few minutes after his admission high lighted the presence of the knife blade at the level of parietal and temporal lobe of her hemisphere right. Result: The patient was operated successfully with extraction of a knife whose blade measured 6 to 7cm. A good postoperative evolution followed. Conscious and without motor deficit, he received a follow-up CT scan on day 7. Then he was released from the hospital with out patient follow-up. Conclusion: Cranial wounds-encephalic by penetration of a bladed weapon are very rare. The CT scan in emergency is the key examination to clarify the location, the number of foreign bodies, as well as brain lesions. They require rapid surgical treatment after CT evaluation. Their prognosis remains reserved regarding the severity of the head trauma, endocranial vascular lesions and infections.