Objective: To compare the efficacies between laparoscopic and open radical gastrectomy and their impacts on immune function of patients. Methods: The clinical data of 114 gastric cancer patients admitted over the past 3 years were retrospectively analyzed. Of the patients, 55 cases underwent laparoscopic gastrectomy (laparoscopy group) while 59 cases were subjected to open gastrectomy (laparotomy group). The postoperative immune function alterations, and intra- and postoperative conditions between the two groups of patients were compared. Results: The determination results for immune function parameters at 24 and 72 h after operation showed the levels of IL-2 and IL-6 in both groups were increased significantly compared with those before operation (all P<0.01), but the increasing degrees of both factors in laparotomy group were greater than those in laparoscopy group (all P<0.05); the peripheral blood levels of CD3+, CD4+, and CD8+ cells in laparotomy group were decreased significantly versus those before operation (all P<0.05), while no significant changes in above T cell subsets were noted in laparoscopy group (all P>0.05). Compared with laparotomy group, the intraoperative blood loss, frequency in analgesic use and postoperative complications in laparoscopy group were significantly reduced, and times to first flatus passage, liquid diet and ambulation as well as length of postoperative hospital stay were significantly shortened (all P<0.05). Conclusion: The efficacy of laparoscopic gastrectomy is better than that of open surgery, because it exerts less impact on immune function and with little systemic damage on the patients.