BACKGROUND Tension pneumothorax of the contralateral lung during single-lung ventilation (SLV) combined with artificial pneumothorax can cause cardiac arrest due to bilateral pneumothorax. If not rapidly diagnosed and managed, this condition can lead to sudden death. We describe the emergency handling procedures and rapid diagnostic methods for this critical emergency situation. METHODS We report a case of bilateral pneumothorax in a neonatal patient who underwent thoracoscopic esophageal atresia and tracheoesophageal fistula repair under the combined application of SLV and artificial pneumothorax. The patient suffered sudden cardiac arrest and received emergency treatment to revive her. The recognition of dangerous vital sign parameters, rapid evacuation of the artificial pneumothorax, and initiation of lateral position cardiopulmonary resuscitation while simultaneously removing the endotracheal tube to the main airway are critically important. Moreover, even though the sinus rhythm was restored, the patient's continued tachycardia, reduced pulse pressure, and depressed pulse oximeter waveform were worrisome. We should highly suspect the possibility of pneumothorax and use rapid diagnostic methods to make judgment calls. Sometimes thoracoscopy can be used for rapid examination; if the mediastinum is observed to be shifted to the right, it may indicate tension pneumothorax. This condition can be immediately relieved by needle thoracentesis, ultimately allowing the safe completion of the surgical procedure. CONCLUSIONS Bilateral pneumothorax during SLV combined with artificial pneumothorax is rare but can occur at any time in neonatal thoracoscopic surgery. Therefore, anesthesiologists should consider this possibility, be alert, and address this rare but critical complication in a timely manner.