Background: – This study analyzes factors and challenges associated with adverse events reporting in Indonesian hospitals. Methods: – The mixed-method study design was used. The quantitative stage is analyzing data from the 2019 Health Facilities Research. The population in this stage is all hospitals in Indonesia, with a sample of 532 hospitals. Data were analyzed using the χ2 test and logistic regression. The qualitative stage, semi-structured interviews were conducted with participants from 6 hospitals in 2 provinces. The data were validated using the triangulation method and analyzed using thematic analysis. Data were collected from September 2023 to April 2024. Results: – The existence of the infection control committee, quality committee, patient safety committee, internal audits, services evaluation and quality control, accreditation status, regional category, and number of beds has been positively associated with adverse events reporting in Indonesian hospitals. The implementation of accreditation standards, the roles of these committees, and evaluation and audit activities contribute to improving quality and patient safety, encouraging incident reporting, which ultimately can reduce adverse events. Challenges to reporting come from both individual and organizational aspects. Conclusions: – These committees should be the main drivers in monitoring AE reporting and implementing evaluation and quality control. Enhancing the role of hospital accreditation through government support as a regulator is also necessary to improve reporting. The main challenge to reporting is the lack of willingness to report. Policymakers and hospital managers must urge to overcome these obstacles by developing an easy-to-use reporting system, eliminating negative perceptions after reporting, and providing appreciation. © 2025