Objective: To examine the mediating effect of resilience on AIDS-related stress and patient-reported outcome among elderly cases with HIV/AIDS, so as to provide the basis for promoting mental health and improving health outcomes of this population. Methods: From June to July 2024, elderly cases with HIV/AIDS receiving treatment in the infectious diseases department of a tertiary-level hospital in Sichuan Province and undergoing follow-up management at 12 community health service centers in Wuhou District, Chengdu City, Sichuan Province, were selected as study participants using convenience sampling method. Data on demographic information, duration since confirmed diagnosis and the most recent CD4+T lymphocyte count were collected through questionnaire surveys. The Chinese versions of the HIV/AIDS Stress Scale, the Chinese versions of the 10-item Connor-Davidson Resilience Scale, and the Patient-Reported Outcome Scale for Elderly HIV/AIDS Patients were used to assess AIDS-related stress, resilience, and patient-reported outcome, respectively. Structural equation modeling was performed using Mplus 8.3 software to analyze the mediating effect of resilience on AIDS-related stress and patient-reported outcome. The Bootstrap method was employed to test the significance of the mediating effect. Results: A total of 424 elderly HIV/AIDS cases were included, with a mean age of (62.04±8.73) years. Among them, 315 (74.29%) were males and 109 (25.71%) were females. The median scores were 23.00 (interquartile range, 11.00) points for AIDS-related stress, 30.00 (interquartile range, 7.00) points for resilience, and 363.45 (interquartile range, 53.03) points for the total score of patient-reported outcome. Resultsof the mediation effect analysis revealed that AIDS-related stress had a direct negative effect on patient-reported outcome (β=-0.608, 95%CI: -0.742 to -0.465). It also exerted an indirect negative effect on patient-reported outcome through the mediating role of resilience (β=-0.258, 95%CI: -0.364 to -0.158), with the mediating effect accounting for 29.79% of the total effect. Conclusion AIDS-related stress among elderly cases with HIV/AIDS can directly or indirectly negatively affect patient-reported outcome through resilience.