The presence of signet-ring cell in endoscopic biopsy is not a good predictor for the diagnosis of signet-ring cell carcinoma of the stomach Introduction: Signet-ring cell carcinoma (SRCC) of the stomach is a histopathological type that has less response to chemotherapy and worse prognosis in patients with advanced gastric cancer, than other types of gastric carcinomas. Diagnostic value of the presence of signet-ring cells (SRC) in the endoscopic biopsy for the diagnosis of SRCC of the stomach, are unknown. Objectives: To calculate the diagnostic values of the presence of SRC in endoscopic biopsy for the diagnosis of SRCC of the stomach in a definitive surgical specimen biopsy. Materials and Methods: Retrospective diagnostic test study to determine the value of the presence of SRC in the endoscopic biopsy for the diagnosis of SRCC of the stomach in the surgical specimen biopsy. Inclusion criteria: Patients who underwent gastric surgery between 1996-2016. We calculated positive and negative predictive values (PPV and NPV), sensitivity, specificity, and positive and negative likelihood ratio (LR+ and LR-) of the presence of SRC in the endoscopic biopsy that predicts the diagnosis of SRCC of the stomach in the definitive biopsy. Confidence intervals (CI) of 95% were defined. Results: The diagnostic values of the presence of SRC in endoscopic biopsy to diagnose SRCC of the stomach in the surgical specimen biopsy were: PPV of 56.1% (95% CI, 47.8-64.1%), NPV of 91.3% (95% CI, 89-93.1%), sensitivity of 55.7% (95% CI, 47.4-63.7%), specificity of 91.4% (95% CI, 89.1-93.3%), LR+ of 6.5 (95% CI, 4.9-8.6) and LR-of 0.48 (95% CI, 0.4-0.6), a positive post-test probability of 56.1% (95% CI, 47.8-64.1%), and a negative post-test probability of 8.7% (95% CI, 6.9-11%). Conclusions: The presence of SRC in the endoscopic biopsy is not sufficient to diagnose SRCC of the stomach. The absence of SRC in the endoscopic biopsy has a high negative predictive value.