Background <p>The aging self-stereotypes are increasingly recognized as a significant psychosocial issue affecting older adults with multimorbidity, particularly those undergoing elective surgery. The aging self-stereotypes can exacerbate postoperative recovery and reduce quality of life. However, factors influencing aging self-stereotypes in this vulnerable population remain underexplored. This study aimed to investigate the level of aging self-stereotypes among elderly patients with multimorbidity undergoing elective surgery and to analyze relevant influencing factors with the goal of laying a foundation for the development of targeted intervention strategies. The findings will help medical staff identify high-risk patients and inform the development of targeted perioperative interventions to improve recovery outcomes and quality of life.</p> Methods <p>This study, which featured a cross-sectional survey design, focused on a total of 188 elderly patients with multimorbidity who underwent elective surgeries at a tertiary A-grade hospital in Chongqing and were recruited through convenience sampling between July 2025 and December 2025. General information questionnaires, the Barthel index, the Cumulative Illness Rating Scale, the Aging Self-Stereotypes Scale, the Fried Frailty Phenotype, and the Control Preference Scale were used in this research. Multiple linear regression was used to identify associated factors. Statistical significance was set at P &lt; 0.05.</p> Results <p>The aging self-stereotypes scores obtained by elderly patients with multimorbidity who underwent elective surgery were 27.697 ± 1.953 points. The results of multiple linear regression analysis identified first-time surgery ( β = 0.143, CI (-0.008, 1.072), P = 0.034), Cumulative Illness Rating Scale score ( β = 0.177, CI (0.230,1.741), P = 0.011), and active decision-making (β = -0.161, CI (-1.900, -0.134), P = 0.024) as influencing factors pertaining to aging self-stereotypes among elderly patients with multimorbidity who underwent elective surgeries, which altogether explained 50.1% of the total variance.</p> Conclusions <p>Elderly patients with multimorbidity who underwent elective surgeries have high aging self‑stereotype scores, which are independently associated with first‑time surgery, multimorbidity burden, and decision‑making preference. A management model that combines multidisciplinary collaboration with family support should be established to reduce negative stereotypes and improve quality of life among these patients.</p>