OBJECTIVE: Very elderly persons admitted to ICUs are at high risk of death. To document life-sustaining interventions (mechanical ventilation, vasopressors, renal replacement therapy) provided in the ICU and outcomes of care. DESIGN: Multicenter, prospective cohort study. SETTING: ICUs of 24 Canadian hospitals. PARTICIPANTS/SETTING: Patients 80 years old or older admitted to the ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One thousand six hundred seventy-one patients were included. The average age of the cohort was 85 years (range, 80-100 yr). Median total length of stay in ICU was 4 days (interquartile range, 2-8 d) and in hospital was 17 days (interquartile range, 8-33 d). Of all patients included, 502 (30%) stayed in ICU for 7 days or more and 344 (21%) received some form of life-sustaining treatment for at least 7 days. ICU and hospital mortality were 22% and 35%, respectively. For nonsurvivors, the median time from ICU admission to death was 10 days (interquartile range, 3-20 d). Of those who died (n = 5 85), 289 (49%) died while receiving mechanical ventilation, vasopressors, or dialysis. The presence of frailty or advance directives had little impact on limiting use of life-sustaining treatments or shortening the time from admission to death. CONCLUSIONS: In this multicenter study, one third of very elderly ICU patients died in hospital, many after a prolonged ICU stay while continuing to receive aggressive life-sustaining interventions. These findings raise questions about the use of critical care at the end of life for the very elderly.