Management of critically ill cancer patients warrants stringent admission criteria and clear concepts concerning duration and limits of intensive care. Recent developments in mechanical ventilation and sepsis therapy can easily be used to improve the outcome of critically ill cancer patients. The incidence and overall prognosis of cancer is constantly growing and, thus, the number of critically ill cancer patients is increasing. Furthermore, novel oncology drugs-in particular immune modulators-produce unexpected and substantial side effects. Therefore, the development of an interdisciplinary algorithm by oncologists and intensivists remains an important and dynamic challenge.