 It has been believed for many years that the scene of cancer patients requiring mechanical ventilation is frustrating. The needed life support measures drain much of health resources and add a significant burden on the patients family. Many factors have been responsible for the high mortality rates among hematologic cancer patients admitted to intensive care unit. Among of these factors, the invasive treatments that are frequently employed in todays intensive care unit. These procedures give chance for development of severe infection and multiple organ failure which are common events in immune-compromised patients e.g. neutropenia and in those exposed to chemotherapy. The most common form of organ failure in those patients is acute respiratory failure which is a major predictor of mortality in that population. The prognosis of such failure may vary depending on its causes and severity, co morbidity, associated acute organ failure and characters of the underlying malignancy. After the recent advances in the field of intensive care and shedding light on the benefits of the noninvasive ventilation in immune-compromised patients, the overall survival rate of cancer patients admitted to intensive care unit are improving. 