BACKGROUND: Pneumonia is among the most serious infections in the elderly. The evaluation of prognosis and predicting the outcome is essential in managing the treatment of patients with pneumonia. OBJECTIVE: Evaluate factors that might affect the mortality of elderly patients hospitalized for community-acquired pneumonia (CAP) in two age groups. DESIGN: Medical record review. SETTINGS: Tertiary care hospital. PATIENTS AND METHODS: The study included CAP patients who were hospitalized during the period from January 2017 and December 2019. The CURB-65 scale was chosen to assess the severity of pneumonia on admission. Multivariate analyses were conducted separately for patients younger than 75 years and 75 years or older. MAIN OUTCOME MEASURES: 30-day mortality, factors associated with mortality. SAMPLE SIZE AND CHARACTERISTICS: 1603 patients with a median age of 74, including 918 women (57%). RESULTS: The 30-day mortality rate was 6.5%. Patients with carbapenem-resistant gram-negative bacteria had lower survival rates ( P <.0001). In the multivariate analysis, age, lung cancer, CURB-65, carbapenem resistance, and duration of hospital stay were associated with mortality in patients aged 75 years or older. Lung cancer, malignant disease, carbapenem resistance, duration of hospital stay and procalcitonin level were associated with mortality under the age of 75. Of 640 sputum cultures tested, P aeruginosa (42%) was the most common pathogen. CONCLUSION: The risk factors that affected mortality differed among patients aged 75 years or older versus younger patients. Our findings are important in determining factors associated with mortality in managing the treatment and follow up of hospitalized CAP patients younger or 75 years of age or older. LIMITATIONS: Single-center, retrospective. CONFLICT OF INTEREST: None.