Objective ·To compare the safety outcomes between immunotherapy continuation and permanent immunotherapy discontinuation in patients with lung cancer who developed immune checkpoint inhibitor-associated myocarditis (ICI-M). Methods ·This single-center retrospective cohort study enrolled 357 lung cancer patients who were diagnosed with ICI-M between June 2016 and August 2024 in Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine. Based on post-ICI-M immunotherapy strategies, patients were categorized into a permanent discontinuation group (n=131) and a continuation group (n=226). The continuation group comprised patients who never interrupted immunotherapy and those who temporarily discontinued but later resumed ICI treatment. The ICI-M recurrence rate and the incidence of other new-onset immune-related adverse events (irAEs) were reported. The severity of initial and recurrent ICI-M was compared, and risk factors for ICI-M recurrence or new-onset irAEs were explored. Multivariable Cox regression analysis was used to evaluate the impact of immunotherapy continuation on major adverse cardiovascular events (MACE). Propensity score matching was performed as a sensitivity analysis to enhance the robustness of the study findings. Results ·The ICI-M recurrence rate was 8.8% (20/226). The clinical severity and peak levels of myocardial injury biomarkers were not higher in recurrent ICI-M than in initial ICI-M. A total of 13.3% (30/226) of patients developed other new-onset irAEs. Patients who experienced ICI-M recurrence or new-onset irAEs had a significantly earlier onset of initial ICI-M (47.0 d vs 71.0 d, P=0.006) and a higher peak creatine kinase-MB (CK-MB) level (4.8 ng/mL vs 2.8 ng/mL, P=0.019). Multivariable Cox regression analysis indicated that immunotherapy continuation did not significantly increase the risk of long-term MACE (HR=0.75, 95%CI 0.28‒1.98, P=0.556), and this result remained consistent across all subgroups (P_interaction>0.05). Sensitivity analysis using propensity score matching confirmed the robustness of this result (after matching: HR=0.93, 95%CI 0.32‒2.70, P=0.894). Conclusion ·Continued immunotherapy after ICI-M in lung cancer patients shows an overall favorable safety profile, with a low ICI-M recurrence rate and no significant increase in MACE incidence. This study provides preliminary evidence to support clinical decision-making; however, large-scale prospective studies are still needed for further confirmation and validation.