ObjectivesA) To examine the long-term survival of critically ill patients compared with the general population in a nationwide sample of patients requiring intensive care; and b) to analyze long-term survival stratified by specific diagnostic subgroups.DesignProspective, inception cohort study.SettingTwenty-five Finnish intensive care units (ICUs) at 17 hospitals, including 13 ICUs in five tertiary care centers.PatientsA consecutive sample of 12,180 adult patients who were admitted to ICUs in 1987. The sample was further divided into seven diagnostic subgroups.InterventionsNone.Measurements and Main ResultsVital status at 5 yrs after admission to an ICU was examined and compared to the age- and gender-adjusted survival of Finland's general population. Among ICU patients, the 5-yr mortality rate was 3.3 times that of Finland's general population (95% confidence interval 3.0 to 3.4). At 2 yrs, the survival rate paralleled that of the general population. At 5 yrs, the relative survival rate of the ICU patients was 66.7%. Cancer was a strong determinant of a poor outcome in multivariate analysis (relative risk 3.17; 95% confidence interval 2.86 to 3.51). The 5-yr mortality rate of the ICU patients compared with the general population was highest among patients admitted to the ICU after intoxication. Trauma victims and patients admitted to the ICU with a cardiovascular diagnosis reached the risk of death of the general population in the shortest time.ConclusionsICU patients reached a life expectancy similar to the general population, on average, 2 yrs after admission. The time after which the survival parallels that of the general population depends, however, on the diagnostic category. (Crit Care Med 1996; 24:1962-1967)