Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sometimes causes severe coronavirus disease 2019 (COVID-19) pneumonia. Here, we report the case of a 35-year-old man with obesity who showed severe respiratory failure from SARS-CoV-2 infection. Immediate high-resolution computed tomography (HRCT) of the chest after endotracheal intubation revealed a significant pneumomediastinum with diffuse ground-glass opacity and consolidation. Ventilator management was difficult with low tidal volume and low positive end expiratory pressure. Therefore, we administered extracorporeal membrane oxygenation (ECMO) to allow lung rest and prevent further progression of the pneumomediastinum and maintain oxygenation. Since implementing ECMO, the patient's oxygenation has stabilized and follow-up HRCT of the chest revealed dramatic improvement of the pneumomediastinum. We gradually tapered off ECMO and employed a pressure-control mode. He was extubated on day 11. To our knowledge, this is the first reported patient who showed complete pneumomediastinum recovery from COVID-19 pneumonia with ECMO.