Background <p>Perioperative neurocognitive disorders (PND) in elderly patients undergoing abdominal surgery seriously affect their prognosis and long-term quality of life, yet the aetiology and pathogenesis of PND remain poorly understood. This study aims to identify the multidimensional physiological, psychological and social factors influencing PND in elderly patients undergoing abdominal surgery, to develop objective biomarkers for diagnosis, and to provide guidelines for treatment response, prognosis, early detection and intervention.</p> Methods <p>This is a multidimensional cohort study of the physiological, psychological, and social influencing factors of PND in elderly patients undergoing abdominal surgery. We plan to recruit more than 500 elderly patients aged 65–90 years who require elective abdominal surgery within 2 years. The study will include one baseline and four follow-up assessments: multidimensional influence factors and outcome indicators will be collected at baseline (T1), at surgery (T2), at discharge (postoperative days 1–7; T3), 1 month (T4), and 3 months (T5). The entire study will run from 11 December 2023 to 31 December 2025.</p> Discussion <p>In this study, a multimodal observation was implemented, combining physiological status and psychosocial factors. To our knowledge, this is the first longitudinal cohort study to examine multidimensional physiological (including biomarkers) and psychosocial factors. This study aims to provide early personalized intervention for elderly surgical patients, reducing the mortality rate and disease burden of elderly patients undergoing major abdominal surgery.</p> Trial registration <p>The protocol is registered at the ClinicalTrials.gov on December 21st, 2023. The trial registration number: NCT06182215.</p>