Cervical emphysema may have its origin in multiple causes. The continuity of the fascial planes connecting the soft tissues of the neck to the mediatinum and retroperitoneum enables the "aberrant air" localized in one of these three areas to spread to the other ones. The otolaryngologist must know the differential diagnosis of the presence of air in the neck, since the ultimate treatment to be given will depend on the etiology involved. We present two clinical cases of cervical emphysema secondary to spontaneous pneumomediastinum. One of the cases is idiopathic while the other one is associated with diabetic ketoacidosis. We analyze this and other causes that can give rise to cervical emphysema.