Objectives: To report a severe case of severe chlorine poisoning inducing acute respiratory distress syndrome (ARDS) and shock required venous-arterial extracorporeal membrane oxygenation (V-A ECMO). Design: Case report. Setting: Pediatric intensive care unit (PICU). Patients: A 11-year-old boy who admitted to our PICU after inhaled chlorine poisoning. Interventions: V-A ECMO. Measurements and Main Results: After inhaling chlorine, the children quickly developed hypoxia, cyanosis and unconsciousness. After high-condition mechanical ventilation, hypoxia was only slightly improved for a short time, and then deteriorated rapidly and shock occurred. The highest oxygen saturation index was 27.3, and the chest X-ray showed extensive diffuse interstitial parenchyma changes. The oxygenation and circulation was recovered quickly under ECMO. The children received methylprednisolone intravenous injection for 3 days, the pulmonary lesions basically recovered 5 days after onset. He was successfully removed from the ventilator 1 day after the successful removal of ECMO. Follow-up 3 months after discharge showed the pulmonary lesions were completely absorbed and there were no other sequelae. Conclusion: Chemical pneumonia caused by chlorine inhalation can lead to severe ARDS or even shock, but the prognosis is often good. ECMO support should be considered when conventional treatment is ineffective.