Background: To describe the clinical presentations, treatment regimen, and outcomes of Pneumocystis jiroveci pneumonia (PJP) among immunocompromised patients at King Faisal Specialist Hospital and Research Center in Saudi Arabia. Materials and Methods: In this retrospective cohort study, patients with a laboratory-confirmed diagnosis of PJP were included. Results: During the study, 42 patients with confirmed PJP were identified. Twenty (48%) patients were HIV-infected, while 22 (52%) were HIV negative. The median T-cell count (CD4) was below 50 cells/mL in HIV patients with PJP at the time of HIV and PJP diagnoses. Graft rejection, cytomegalovirus (CMV) reactivation, and lymphopenia were associated with the development of PJP in transplant recipients; and high-dose steroids for non-transplant patients. The allcause mortality at 90 days was lower in individuals with HIV-related PJP, compared to those with other predisposing conditions (10% and 32%, respectively; P=0.085). No specific risk factors were independently associated with the increased risk of mortality. Conclusion: PJP remains an important cause of morbidity and mortality in immunocompromised patients, with a higher mortality rate reported in non-HIV patients.