BACKGROUND Previous studies have shown that the outcome of lung cancer patients who were admitted to the Intensive Care Unit (ICU), especially those requiring mechanical ventilation, is extremely poor. The present study was conducted in order to assess the outcome of a recent cohort of lung cancer patients admitted to the ICU with acute respiratory failure. METHODS A retrospective analysis of the medical records of 105 lung cancer patients who were admitted to the ICU between January 2008 and January 2011 was performed. Severity of illness on the first day of ICU admission was assessed using the acute physiology and chronic health evaluation (APACHE) II and the sequential organ failure assessment (SOFA) scoring systems. Associated organ failure was determined according to the Knaus criteria. RESULTS Eighty four (80%) patients were diagnosed with non-small cell lung cancer, 14 (13.3%) with small cell lung cancer, one patient with mesothelioma, and in the remaining 6 patients, the type of lung cancer could not be determined. Significant factors on admission were APACHE II and SOFA scores, poor performance status and severe comorbidity. During ICU stay, the main risk factors for poor outcome were the long term mechanical ventilation duration, use of vasopressors, more than two organ system failures and septic condition. The overall ICU, hospital and 6-month mortality rates were 44.7% (47/105), 56.1% (59/105) and 77.1% (81/105) respectively. CONCLUSIONS The present data show that the medical intensive care unit outcome of lung cancer patients is improving. Further studies of patients selected to ICU admission are needed to assess long-term mortality, quality of life, ability to continue chemotherapy and economic cost.