Occidental countries are affected by a demographic ageing. The growing number of elderlies in the intensive care units (ICU) reflects this phenomenon. The physicians must deal with many medical, ethical and economical questions about the care policy provided to these patients. Despite the various definitions or thresholds used to characterize elderly patients, studies analyzing the long-term survival and quality of life do not allow us from applying care restrictions on an age basis only. Tools to improve the ability to estimate prognosis during the triage process or during an ICU stay are necessary. Currently no prediction model can decide about the ICU admission or about the treatment to provide to elderly patients without the opinion of an ICU specialist.