Background: An important aspect of improving outcomes for patients with malignancy is the provision of critical care during periods of acute deterioration. Decisions regarding whether advanced cancer patients should be admitted to the ICU is based on a complex suite of considerations, including short- and long-term prognosis, quality of life, and therapeutic options to treat cancer. We set to describe demographic, clinical, and survival data and to identify factors associated with short- and long-term mortality in critically ill advanced cancer patients with non-elective admissions to general ICUs. Methods: Critically ill adult (≥18-year-old) cancer patients non-electively admitted to the intensive care units at the American University of Beirut Medical Center (AUBMC) between August 1st, 2015, and March 1st, 2019, were included. Demographic, clinical, and laboratory data was prospectively collected from first day of ICU admission up to 30 days after discharge. This study was strictly observational and clinical decisions were left to the discretion of the ICU team and attending physician. Results: Two hundred seventy-two patients were enrolled in the study between August 1st, 2015, and March 31st, 2019, with an ICU mortality rate of 43.4%, with the number rising to 59% within 30 days of ICU discharge. Mean length of stay in our ICU was 14 days with an interquartile range of 1 to 120 days with a median overall survival of 22 days since date of ICU admission. The major reasons for unplanned ICU admission were sepsis/septic shock (54%) and respiratory failure (33.1%). COX regression analysis showed that sepsis, uncontrolled malignancy, ARDS, multi-organ failure, use of vasopressors, use of mechanical ventilation are major predictors of poor prognosis. Direct admission from the ED was associated with a higher risk of mortality (48.9%) than being transferred from the floor (32.6%) (p = 0.014). Additionally, mortality in patients with solid malignancies (47.6%) was higher than those with hematologic malignancies (34.1%) (p = 0.0048). Conclusions: Patients admitted to the ICU in a tertiary care center in the MENA region are at high risk for short term mortality.