Purpose: To evaluate the variables associated with mortality of patients with community-acquired pneumonia who require mechanical ventilation and to determine the attributable morbidity and intensive care unit (ICU) mortality of community-acquired pneumonia. Material and Methods: Retrospective cohort study carried out in 361 ICUs from 20 countries including 124 patients who required mechanical ventilation on the first day of admission to the hospital due to acute respiratory failure secondary to severe community-acquired pneumonia. To assess the factors associated with outcome, a forward stepwise logistic regression analysis was performed, and to determine the attributable mortality of community-acquired pneumonia, a matched study design was used. Results: We found 3 independent variables significantly associated with death in patients with community-acquired pneumonia requiring mechanical ventilation: simplified acute physiological score greater than 45 (odds ratio, 5.5 [95% confidence interval, 1.7-12.3]), shock (odds ratio, 5.7 [95% confidence interval, 1.7-10.1]), and acute renal failure (odds ratio, 3.0 [95% confidence interval, 1.1-4.0]). There was no statistically significant difference in ICU mortality among patients with or without community-acquired pneumonia (32% vs 35%; P = .59). Conclusions: Community-acquired pneumonia needing mechanical ventilation is not a disease associated with higher mortality. The main determinants of patient outcome were initial severity of illness and the development of shock and/or acute renal failure.