The occurrence of cervicofacial subcutaneous emphysema and pneumomediastinum is very rare but can be potentially life-threatening. These complications can happen during or after bronchoscopic or dental procedures, esophageal rupture or perforation, infections involving the head and neck and alveolar rupture in the setting of an inciting event such as asthma. The symptoms can appear promptly after the inciting event, but can also be delayed or do not reach maximal intensity for hours. Cervicofacial subcutaneous emphysema usually occurs during or within minutes to hours after dental treatment and can be easily misdiagnosed as post-procedure swelling or an allergic reaction. We report a 36-year-old male who underwent dental treatment for a fractured left lower molar tooth and subsequently developed extensive subcutaneous emphysema and pneumomediastinum. The purpose of this report is to bring attention to the fact that obtaining an accurate diagnosis for this condition is very important and management in a timely manner can prevent serious complications.