We report the 7th case of a traumatic extrapleural hematoma that developed in an anticoagulated patient with a throacic blunt trauma and rib fractures, and required an emergency surgical treatment. Extrapleural hematoma is a rare and life-threatening condition characterized by a collection of blood between the pleura parietalis and the endothoracic fascia. Related symptoms and chest x-ray findings are not characteristic and may present several hours after the injury, leading to delayed diagnosis and treatment. Ethiological, surgical and prognostic implications of this finding are briefly discussed.