OBJECTIVE: Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) is a serious complication in patients with severe COVID-19. This study investigated the incidence and risk factors for CAPA in patients with severe COVID-19 at Osaka Public University Hospital from April 2020 to November 2021. METHODS: This retrospective study involved patients with CAPA patients requiring invasive ventilation who were diagnosed according to the European Confederation of Medical Mycology and the International Society of Human and Animal Mycology criteria. Patients were classified into the CAPA and non-CAPA groups. Data collected included age, sex, body mass index, smoking history, underlying disease, length of hospital stay, steroid and other drug use, extracorporeal membrane oxygenation use, and outcome. Univariate analysis was used to identify risk factors associated with CAPA. RESULTS: Of the 256 COVID-19 patients, 187 required invasive ventilation, and eight were diagnosed with CAPA. The incidence of CAPA among COVID-19 patients requiring ventilator management was 4.28 %. Tracheostomy was performed in seven patients, and Aspergillus spp. was detected in six, of whom four were confirmed to have A. fumigatus. CAPA mortality was high, with six of eight patients dying. Univariate analysis showed COPD (P = 0.04) and chronic liver disease (P = 0.04) as common comorbidities. β-D-glucan positivity, tracheostomy, prolonged hospitalization, prolonged steroid use, and death (P <
0.01) were more prevalent in the CAPA group. CONCLUSIONS: When bronchoscopy is unfeasible, early diagnosis using serum Aspergillus antigen measurement and imaging is essential, particularly for patients with COPD, liver disease, or risk factors like prolonged hospitalization or steroid use post-COVID-19 treatment.