Subcutaneous emphysema occurs when air enters the soft tissue, which usually appears in the soft tissues of the chest wall or neck. It may also arise from pneumothorax or skin lacerations after trauma or other reasons. Mediastinal emphysema may be either associated with subcutaneous emphysema or seen alone. The air in the mastoid cells may spread from the retropharyngeal region or various neck compartments into the mediastinum. Usually, no severe neurological or clinical findings are observed except crepitation on palpation. We present a case report of a mastoid fracture as a rare cause of cervical subcutaneous and mediastinal emphysema.