Background: A sentinel lymph node (SLN) biopsy is an interesting issue in the field of surgical oncology and has recently been introduced to the treatment of gastric cancer. The purpose of this study is to assess accuracy, sensitivity, specificity, and false negative rates (FNRs) of SLN biopsies, and to ascertain whether or not this procedure is useful for locally advanced gastric cancer.Methods: From December 2013 to March 2014, 22 patients with gastric cancer were enrolled in this study. After laparotomy, patent blue was injected around the tumor subserosaly, resection was then done, and SLNs were detected on a back table. Afterward, D2 dissection was carried out. Finally, SLNs and other specimens were submitted for permanent pathology.Results: SLNs were detected in 20 of 22 patients. The total number of SLNs was 87. SLNs were positive in 7 patients, and the total number of positive SLNs was 17. In three patients, the SLNs were negative, whereas other LNs were positive, with an FNR of 15%. 18 patients received neoadjuvant. Complete pathologic responses with negative LNs were seen in 3 patients. Accuracy, sensitivity, specificity, and negative predictive values were 80%, 66%, 90%, and 76%, respectively.Conclusions: This research demonstrated that SLN mapping in advanced gastric cancer is an appropriate method with acceptable levels of accuracy, sensitivity, and negative predictive values, even in those patients who received neoadjuvant treatment