Objectives:There is no consensus on whether mechanical ventilation should be initiated for advanced age with community-acquired pneumonia (CAP). This study investigated the effects of age on the outcomes of mechanical ventilation in the emergency department (ED) for advanced age with CAP.Methods:We retrospectively investigated the medical records of advanced age (age, ≥ 65 years) with CAP who required mechanical ventilation in the ED of our hospital between January 2006 and December 2012. The patients were divided into 65 to 74, 75 to 84, and 85 years or older age groups. The following outcomes were measured: number of patients weaned from mechanical ventilation, in-hospital mortality, ventilator-free days, and intensive care unit days. Multiple logistic regression analysis was used to identify risk factors associated with mortality and weaning from mechanical ventilation.Results:Seventy-one patients (mean age, 79.5 years) were included. The overall in-hospital mortality rate was 43.7%. No significant differences were observed among the 3 groups with regard to weaning from mechanical ventilation (P = .59), in-hospital mortality (P = .90), ventilator-free days (P = .83), or intensive care unit days (P = .12). Age was not significantly associated with weaning from mechanical ventilation or in-hospital mortality among advanced age. Diabetes mellitus was an independent factor for weaning from mechanical ventilation (P = .048) and was relatively associated with mortality (P = .051).Conclusions:Age, in itself, may not be a factor limiting the initiation of mechanical ventilation in the ED in advanced age with CAP. Further studies should determine appropriate indications for mechanical ventilation in the ED for these patients.