Elderly patients are increasingly opting for intensive care unit (ICU) treatment with mechanical ventilation (MV). The aim of this study was to review specific aspects of MV in the older elderly (80-yrs-old and older). We retrospectively studied all patients who underwent MV during a 2-year-period in our respiratory ICU. Older elderly were compared with younger patients. Of 478 patients admitted to our unit, 58 underwent endotracheal ventilation (ETV) and 243 noninvasive ventilation (NIV). At the time of admission, older elderly patients (n = 106) were more severely ill than the younger ones, according to simplified acute physiology scores (SAPS). The history of older patients was characterized by a lower frequency of neurological abnormalities, and in the ETV group, a lower frequency of days previously spent in hospital. NIV was performed more often in older elderly (64%) than in younger patients (47%) and for a shorter time-period (8 compared to 10 days). The ICU mortality rate was higher in the older patients than in the younger ones in the overall population admitted to the unit (38 compared to 12%) and in the NIV population (21 compared to 9%) but not in the ETV population (40 compared to 44%). Long-term survival (2 yrs) was low (12%) in the older patients admitted to the unit. Several studies from the literature were reviewed. All authors agreed that age alone should not be a criterion to exclude the older elderly from intensive care, regardless of whether they found them to have the same or a poorer prognosis than younger patients. Selection biases are rarely studied. Our results indicate that some selection procedures on admission to the intensive care unit and before endotracheal ventilation are present despite the absence of any selection policy in our department. This selection enables us to obtain results from older populations which are as good as those from nonselected younger populations. When its use is practicable, noninvasive ventilation is associated with less discomfort, fewer complications and better short-term results than is endotracheal ventilation. In all cases, the long-term prognosis is poor.