BACKGROUND: Immune checkpointinhibitors (ICIs)-associated cardiotoxic events (CEs) are of increasing concern.Existing research about glucocorticoids (GCs) on immunotherapy focused on ICIs'efficacy and patients' outcome. The influence of GCs on ICIs-associated CEs andmyocardial damage (MD) remains unknown. RESEARCH DESIGN AND METHODS: This single-centerretrospective study included patients treated with ICIs from 2018 to 2022, withfollow-up period ending on 30 June 2023. The incidence, risk factors of ICIs-associated CEs, especially MD were described.Additionally, the impact of baseline GCs was assessed by propensity scorematching (PSM) to mitigate intergroup differences and ensure comparability. RESULTS: Among 1018 patients, 204(20.04%) experienced ICIs-associated CEs, including 71 (6.97%) with MD. Themean follow-up time was 40.39 (95%CI 38.47-42.31) weeks. The median time toonset of MD was the shortest at 12.57 weeks (IQR 5.29-25.14). Tumor type,co-medication with platinum and angiogenesis inhibitors may beinfluential factors of MD. After PSM, the relative risks of CEs (OR 0.4625,95%CI 0.2514-0.7235, CONCLUSION: GCs ≥20 mg during the first ICIstreatment cycle is significantly associated with the reduced risks of bothICIs-associated CEs and MD.