Objective To explore risk factors for death among critically ill patients in comprehensive hospitals so as to improve the diagnosis and treatment level for these patients. Methods Data of 1735 patients who were admitted to intensive care unit (ICU) during the period of 2005 to 2010 were retrospectively analyzed. Among these patients, there was 198 ICU death and 135 post-ICU death. The characteristics of disease distribution were investigated in different age groups (＜60, 60-80, ≥60 years) among 198 ICU death patients. The death rate and number of organ failure were compared between ICU death and post-ICU death patients. The risk factors for death were analyzed. Results The death rate was significantly higher in elderly group than in non-elderly group, with difference between the two groups (P＜0.01). The death rate displayed an elevating tendency with age increase. Number of organ failure was positively correlated with death rate, which was almost up to 100% when there were more than five organ failures.When organ failure number was less than three, the ICU death rate was significantly less than post-ICU death rate (P＜0.01). According to the distribution of organ dysfunction, the incidence of cardiovascular dysfunction was the highest (51.8%), but with lower death rate. The death rate was comparatively higher in patients with blood system and renal dysfunction (59.3% and 58.7% respectively). The failure organ was different between ICU death and post-ICU death. Conclusion The reduction of death rate in elderly patients ≥60 years is fundamental for reduction of death rate of critically ill patients. To define the original disease and dysfunction organs, to actively control disease development into multiple organ dysfunction syndrome, and to protect main organ functions play important roles in the treatment of critically ill patients.