Purpose: The development of technologies for the prolongation of life has resulted in an increase in the number of older ventilated patients in internal medicine and chronic care wards. Our study aimed to determine the factors influencing the outcomes of older ventilated patients in internal medicine wards. Methods: We performed a prospective observational cohort study including all newly ventilated medical patients aged 65 years and older over a period of 18 months. Data were acquired from computerized medical records and from an interview of the medical personnel initiating mechanical ventilation. Results: A total of 554 underwent mechanical ventilation for the first time during the study period. The average age was 79 years, and 80% resided at home. Following mechanical ventilation, 8% died in the emergency room, and the majority of patients (351; 63%) were hospitalized in internal medicine wards. In-hospital mortality was 64.1%, with 48% dying during the first week of hospitalization. Overall 6-month survival was 26%. We found that a combination of age 85 years and older, functional status prior to ventilation, and associated morbidity (diabetes with target organ injury and / or oncological solid organ disease) were the strongest negative predictors of survival after discharge from the hospital. Conclusion: Mechanical ventilation at older age is associated with poor survival and it is possible to identify factors predicting survival. In the midst of the Covid-19 pandemic, the findings of this study may help in the decision-making process regarding mechanical ventilation for older people.