Cervicofacial subcutaneous emphysema is a rare complication of tonsillectomy that often resolves spontaneously but may progress to obstruct upper airways or spread to the thorax causing pneumomediastinum or pneumothorax. The mechanisms by which subcutaneous emphysema and pneumomediastinum may develop after tonsillectomy are poorly understood. A case of a 21-year-old female undergoing routine adenotonsillectomy, who developed cervicofacial emphysema and pneumomediastinum, is presented. Possible pathogenetic mechanisms and treatment options are discussed.