While it is well-known that adjunctive corticosteroid use improves the outcome of moderate-to-severe Pneumocystis jirovecii pneumonia (PcP) in patients with human immunodeficiency virus (HIV), there is limited data on its efficacy in non-HIV-infected patients with PcP. Patients undergoing fiberoptic bronchoscopy with bronchoalveolar lavage for suspected PcP from January 2007 through December 2010 were reviewed retrospectively. We compared demographics, clinical characteristics, and outcomes in 88 non-HIV infected patients with moderate-to-severe PcP with (n = 59) and without (n = 29) adjunctive corticosteroid use. Outcomes of PcP were assessed by respiratory failure and 30-day and 90-day all-cause mortality. Survival curves were analyzed by the Kaplan-Meier method and estimated by the log-rank test. All cause mortality of moderate-to-severe PcP at 90 days was lower in the solid organ transplant recipients than in all other patients (6/26 [23%] vs. 34/62 [55%]; P = 0.006), and mortality at 30 days was lower in patients with hematologic malignancies (4/26 [15%] vs. 24/62 [39%]; P = 0.03). The outcomes of PcP were not significantly different in moderate-to-severe PcP patients with and without adjunctive corticosteroid use, regardless of recent corticosteroid use. Survival analysis of PcP patients with and without corticosteroid use by the Kaplan-Meier method also did not reveal any difference (log-rank test, P = 0.81). There was again no difference within the subgroup of PcP patients with solid organ transplants. Adjunctive corticosteroid use may not improve the outcome of moderate-to-severe PcP in non-HIV infected patients.