Post-traumatic infectious complications of the frontal sinus occur more frequently after multiple fractures than after isolated fractures. The greatest frequency is found with open traumas of the sinus, due to the presence of foreign bodies and to bone and mucosal destruction. Such infectious complications are curatively treated both medically and surgically, to eliminate the bony and mucosal infection and to restore the normal physiology of the frontal sinus. Stress is laid on the preventive treatment, especially on the quality of the initial surgical treatment, either by restoring the sinus with gauging of the nasal-frontal canals, or by eliminating the sinusal function by a canalization which appears preferable to exclusion by obliteration.