BACKGROUND: Immune checkpoint inhibitors (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 and myocardial damage (MD) remains unknown. RESEARCH DESIGN AND METHODS: This single-center retrospective study included patients treated with ICIs from 2018 to 2022, with follow-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 score matching (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. The mean follow-up time was 40.39 (95% CI 38.47-42.31) weeks. The median time to onset of MD was the shortest at 12.57 weeks (IQR 5.29-25.14). Tumor type, co-medication with platinum and angiogenesis inhibitors may be influential 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 ICIs treatment cycle is significantly associated with the reduced risks of both ICIs-associated CEs and MD.