Objective To explore the effect of comprehensive geriatric assessment on the whole process management of elderly patients undergoing daytime surgery. Methods Elderly patients undergoing daytime surgery at Beijing Geriatric Hospital between April and September 2024 were included and randomly divided into a control group and a trial group using a random number table method. The control group received routine care for the whole process of daytime surgery, while the trial group received daytime surgery routine care, comprehensive geriatric assessment and corresponding intervention measures. The basic information, delayed discharge, adverse events of daytime surgery, and patient satisfaction of the two groups of patients were compared. Results A total of 84 elderly patients were ultimately included, with 42 in the trial group and 42 in the control group. There was no statistically significant difference in age, gender, number of comorbidities, number of oral medications, American Society of Anesthesiology anesthesia grading, and daytime surgical procedures between the two groups of patients (P>0.05). The incidence of postoperative adverse events in the trial group was lower than that in the control group (11.90% vs. 30.95%), and the patient satisfaction rate was higher than that in the control group (100.00% vs. 85.71%), with statistically significant differences (P<0.05). There was no statistically significant difference in the delayed discharge rate between the two groups (P>0.05). Conclusion For elderly patients undergoing daytime surgery, embedding comprehensive geriatric assessment in the whole process management can reduce postoperative adverse events and improve patient satisfaction, which is worth promoting.