Tension pneumothorax is a rare complication of the apnea test using the apneic oxygenation method. In reported cases, it has been attributed to massive air trapping beyond a supplemental oxygen cannula that was obstructing the airway. We report a case of tension pneumothorax, pneumomediastinum, and pneumoperitoneum that developed during the apnea test as a result of direct airway perforation by the supplemental oxygen cannula. We review the literature concerning catastrophic airway complications associated with the apneic oxygenation method and suggest ways to avoid them.