Aims: The acute respiratory distress syndrome (ARDS) is a frequent condition following pneumonia in immunocompromised cancer patients. Extracorporeal membrane oxygenation (ECMO) may serve as a rescue therapy in refractory ARDS but has still not been studied in predominantly leuco- and thrombocytopenic cancer patients. Patients and Methods: In this monocentric, retrospective, observational study, we assessed all cancer patients treated with ECMO for ARDS between 2013 and 2017. Results: 25 patients, 11 of whom underwent haematopoietic stem cell transplantation (SCT), were analysed. The main reason for ARDS was pneumonia in 72%. All patients were under invasive ventilation at ECMO. All but 9/3 patients suffered from leuco-/thrombocytopenia due to anti-cancer treatment or underlying disease. Overall, 17 patients (68%) died on ECMO, whereas 5 patients survived to hospital discharge (20%). All patients after recent allogeneic (allo-)SCT have died. 4 patients experienced severe bleeding events. Conclusions: Discouraging survival rates in patients treated after allo-SCT do not support the use of ECMO for ARDS in this patient subgroup. On the contrary, cancer patients in at least stable disease otherwise eligible for full-code intensive care unit management, even those with severe thrombocytopenia, may be potential candidates for ECMO in case of severe ARDS failing conventional measures.