BACKGROUND The study aims to explored the impact of short-term mindfulness meditation training on physiological and psychological stress levels in patients with gastrointestinal tumors during the perioperative period. MATERIAL AND METHODS We randomly allocated 78 participants to either the experimental group (n=39) or the control group (n=39). The control group received perioperative nursing, while the experimental group engaged in a daily mindfulness meditation practice from the second day of admission until the fifth day after surgery, excluding the day of surgery. The pre- and post-intervention physiological stress levels of serum cortisol, blood pressure, and heart rate were assessed. The State Anxiety Inventory Scale (SAI), Visual Analog Scale (VAS), and Five Facet Mindfulness Questionnaire (FFMQ) were utilized to measure psychological stress. The rehabilitation and additional indices were also observed. RESULTS The serum cortisol and SAI in both groups showed an increasing trend on the 3rd day after surgery, followed by a decreasing trend. On the 5th day after surgery, significant reductions were observed in cortisol (t=-2.054, P=0.043) and VAS (t=-2.29, P=0.025). The experimental group exhibited lower levels of cortisol and SAI compared to the control group, while the FFMQ score gradually increased with intervention. Additionally, the experimental group demonstrated significantly shortened hospital stays (t=-3.157, P=0.002) and reduced requirements for postoperative analgesics. CONCLUSIONS Perioperative short-term mindfulness meditation can improve the mindfulness ability of patients with gastrointestinal tumors, relieve anxiety and tension, reduce serum cortisol, regulate blood pressure and heart rate, generally reduce perioperative psychological and physiological stress responses, and control hospital time and cost.