ObjectiveTo analyze the clinical characteristics, prognosis and predisposing factors of coronavirus disease 2019 (COVID-19) associated pulmonary mucormycosis (CAPM), so as to improve people's understanding of the disease.MethodsFrom from September 1, 2021 to July 31, 2024, 11 patients with CAPM who were hospitalized in Beijing Chaoyang Hospital affiliated to Capital Medical University were retrospectively collected, and 22 patients with non-CAPM were included after matching according to the ratio of 1:2. The clinical manifestations, laboratory examinations, imaging features, tracheoscopy, treatment and prognosis of the two groups were analyzed. ResultsThe average age of patients in CAPM group was 59.5 ± 10.6 years, with 81.8% of males; diabetes mellitus (90.9%) was the most common complication. In CAPM group, the median time after the occurrence of mucor after COVID-19 was 13.0 (10.0, 24.0) days. The utilization rate of glucocorticoids in the CAPM group was 63.6% (7/11), which was significantly higher than that in non-CAPM group (13.6% (3/22)), and the difference between the groups was statistically significant (P=0.006). The C-reactive protein level in CAPM group was significantly higher at 93.90 (75.00, 129.00) mg/L than that in non-CAPM group at 26.10 (4.83,114.03) mg/L, with a statistically significant difference (P=0.040). The CD4+T lymphocyte counts and B lymphocyte counts in CAPM group were 223.00 (66.75,336.75)/µL and 32.00 (21.75,55.25)/µL, respectively, which were significantly lower than those in the non-CAPM group (394.00 (206.00, 610.00)/µL and 112.50 (56.00,159.25)/µL, with statistical differences between the groups (P=0.040, P=0.040). In terms of imaging, the main imaging findings were the involvement of multiple lobes in both groups. 63.6% (7/11) of patients with pulmonary aspergillosis in CAPM group were significantly higher than those(4/22,18.2%) in non-CAPM group (P=0.017). The incidence of dyspnea in CAPM group was significantly higher than that in non-CAPM group (90.9% vs. 50.0%, 0.027%).ConclusionThe proportion of glucocorticoid use and the proportion of pulmonary aspergillosis in CAPM group are significantly higher, and they are in a more serious state of immunosuppression. Once combined with pulmonary aspergillus , the mortality rate is higher.