Purpose: The prediction of outcome for patients with gastric cancer is determined largely by the presence of lymph node metastases, which could be detected by sentinel lymph node (SLN) biopsy (SLNB). The purpose of this work was to determine the feasibility of SLNB in patients with gastric cancer for the assessment of regional lymph node status, including performing immunohistochemical (IHC) staining of SLN tissue. Methods: We reviewed 137 consecutive patients with operable gastric cancer over a 10-year period using a retrospective (to examine skip metastases) and prospective (to evaluate successful mapping) study design. SLNs were mapped, biopsied and subsequently explored by routine hematoxylin & eosin (H&E) staining and by IHC staining using a cytokeratin 8/18 antibody. Results: The retrospective study showed a low incidence of skip metastases (3.7%). Mapping of SLNs in the prospective study was highly successful (98.2%). During the prospective study, IHC examination of SLNs from 56 patients showed statistically significant change in disease stage. Conclusion: This study demonstrated highly successful mapping and biopsy of SLNs (98.2%), as well as highest specificity (100%), sensitivity (100%) and accuracy (100%) to predict metastasis in the surrounding lymph nodes of gastric carcinoma. In addition, we believe that IHC study might enable "ultra staging" and additional selection of patients for further cancer treatment