As prognosis of critically ill cancer patients has markedly improved during the last decades, a general reluctance to admit critically ill cancer patients to the ICU cannot be justified anymore. This development leads to an increasing number of patients classified as prone to “full code management,” which refers to the use of the whole armamentarium of intensive care medicine, comprising also respiratory or circulatory support by ECMO, if applicable. The term “ECMO” refers to either respiratory or circulatory support. As respiratory failure is the leading cause for ICU admission in cancer patients and is associated with high mortality, respiratory ECMO has been mainly used in selected patients suffering from severe pneumonia, ARDS, diffuse alveolar hemorrhage, or involvement of the respiratory system by the underlying disease. General ECMO indication criteria also apply to cancer patients, provided that the status of the underlying malignancy allows for “full code” intensive care management. Outcome of critically ill cancer patients in need for ECMO is however worse compared to patients not suffering from malignancy. There are no defined criteria for predicting prognosis; it seems to be prudent, however, to prefer ECMO in patients in need of a therapeutic bridge to overcome a reversible acute and life-threatening complication. Patients undergoing hematopoietic stem cell transplantation are no good candidates for ECMO therapy during the peri-transplant period due to very poor outcome. Management of cancer patients during ECMO can be challenging due to immunosuppression leading to an increased risk for infectious complications as well as due to an increased risk for bleeding complications due to thrombocytopenia or derangements of plasmatic coagulation. An individually tailored anticoagulation concept should therefore be applied. If prerequisites for successful management cease to apply, withdrawal of care will be appropriate. In this situation, a clear communication strategy and adequate palliative care measures should be applied in a standardized way.