Introduction: Lung cancer remains the leading cause of cancer mortality worldwide. Despite lung cancer`s poor prognosis, lung cancer patients are increasingly admitted to medical intensive care unit (MICU) for critical illness. The aim of the this study was to assess the outcome of lung cancer patients who admitted to a MICU and to identify the measurable predictors of their MICU outcome. Methods: We retrospectively evaluated MICU outcomes and identified risk factors for MICU mortality in consecutive patients with lung cancer admitted to the MICU between 2007 and 2012. A total of 105 lung cancer patients were included during the study period. The mean age±SD at MICU admission was 71.2±8.6 yrs (85% males, 15% females). Of 105 included patients, 78 had non-small cell lung cancer. Extensive disease (NSCLC stage III, IV, disseminated small cell lung cancer) was diagnosed in 98 patients (93%). The MICU mortality was 62% (64 patients). The main reasons for MICU admission were acute respiratory failure (60%). Results: The independent predictors of poor MICU outcome were: diabetes mellitus on past history (p=0.025); Acute Physiology And Chronic Health Evaluation III (p=0.012); the need for mechanical ventilation (p=0.012); the use of vasopressor (p=0.000); complication of ARF (p=0.003), presence of multiorgan failure (p=0.000). Conclusions: We found that MICU mortality was not influenced by the type and stage of lung cancer but increased with the severity of the organ failure at MICU admission.