© 2015, Sociedad Chilena de Infectologia. All rights reserved.Background: Respiratory infection caused by Pneumocystis jiroveci is a common opportunistic infection in patients with human immunodeficiency virus (HIV) with CD4 counts < 200 cells/mm3. However, it has also been reported in patients with other causes of immunosuppression. Objectives: To compare the characteristics, severity and mortality of respiratory infection by P. jiroveci in patients with and without HIV infection. Methods: Retrospective cohort follow-up of adult patients admitted to our hospital with infection by P. jiroveci since 2006 to 2013. Results: We included 82 patients with respiratory infection by P. jiroveci of which 55% (45) were not infected with HIV. In this group, 68.8% (31) had diagnosis of cancer and 20% (9) received solid-organ transplant. 57.9% (26) were hospitalized in an intensive care unit. 42.2% (19) suffered multiple organ failure (MOF), 46.7% (21) required mechanical ventilation (MV) and 40.9% (18) inotropic drugs. Mortality was 33.3% (15). Statistically significant differences were observed between groups in age (p <0.001), requirement of MV (p <0.001) inotropic drugs (p 0.001) and MOF (p <0.001). Mortality was higher in the HIV-positive group, reaching statistical significance (p 0.007). Conclusion: Pneumocystis pneumonia mortality was higher in patients without HIV, who suffered more complications and progression to respiratory failure with MOF.