Abstract Background The correlation and influencing factors of preoperative anxiety, postoperative pain, and delirium in elderly patients undergoing gastrointestinal cancer surgery were explored with the Beck Anxiety Inventory (BAI) scale, 10-point Visual Analogue Scale (VAS), and Confusion Assessment Method Chinese Reversion (CAM-CR) scale. Methods A total of 120 patients aged 65 years old who receiving gastrointestinal cancer surgery were enrolled in the study. Perioperative anxiety, pain, and delirium were assessed by the BAI scale, VAS scale, and CAM-CR scale, respectively. The correlation and influencing factors of preoperative high anxiety, postoperative high pain, and postoperative delirium were analyzed. Results Preoperative high anxiety had a moderate positive correlation with postoperative high pain (P