Aim:To discuss the iatrogenic cervicofacial emphysema and pneumomediastinum after endodontic treatment of maxillary premolar. Summary:A 25-year-old female was referred to the department with considerable swelling on the right side of face. She gave a history of progressive swelling with mild difficulty in breathing and swallowing 15 minutes after endodontic treatment of an upper right first premolar. The tooth was accessed by a private practitioner using high speed air driven handpiece without the use of rubber dam and compressed air was used to dry the canals. On examination, swelling extended from right peri-orbital region to the neck bilaterally. It was soft, non-erythematous and showed crepitations without pain. The microbiological tests showed no evidence of infection. A Computed tomogram of the thoracocervicofacial region confirmed the diagnosis of cervicofacial emphysema with pneumomediastinum. She was kept on antibiotics and analgesics for 7 and 3 days respectively. Patient showed regression of swelling, dyspnoea and dysphagia on follow up visit after 48 hours.Key learning point:Early diagnosis and management of such cases is of extreme importance to prevent possible cardiopulmonary complications and infections. Computed tomography scans are very useful in diagnosis and to determine the extension of air into the tissue spaces.