Non-Hodgkin's lymphoma initially presenting as a solid huge mediastinal mass does not frequently occur. Although nowadays many patients with high-grade (aggressive) malignant lymphoma can be cured using a combination of immuno- and chemotherapy, rapid progression and acute complications caused by the tumor mass itself may necessitate additional invasive treatment. We report a case of successful extracorporeal membrane oxygenation treatment in a 43-year-old woman with acute respiratory insufficiency due to a huge mediastinal non-Hodgkin's tumor.