OBJECTIVE The usefulness of gastric juice CA 19-9 and carcinoembryonic antigen (CEA) levels in the diagnosis of gastric carcinoma is controversial. There is only one study related with their prognostic value. In this study the clinical significance of gastric juice CA 19-9 and CEA levels in patients with gastric carcinoma was investigated. METHODS Preoperative serum and gastric juice CA 19-9 and CEA concentrations were measured in 139 patients with gastric carcinoma, 54 patients with benign gastroduodenal disease and as the 'healthy' control group 46 patients with inguinal hernia and with no other pathology. RESULTS In all groups the mean gastric juice levels of CA 19-9 and CEA were significantly higher than the serum levels. The gastric juice CA 19-9 levels were not different between groups. Gastric juice CEA levels of the gastric carcinoma group were significantly higher than those of the benign gastroduodenal disease group (P=0.007) and had a tendency to increase when compared to those of the control group (P=0.064) whereas there was no significant difference between the benign gastroduodenal disease and the control group. The cut-off values of gastric juice CA 19-9 and CEA were 440U/ml and 320ng/ml and the positivity ratios of these markers in gastric carcinoma patients were 16.5 and 27.3%, respectively. There was no significant relationship between the histopathological features and the gastric juice CA 19-9 or CEA positivities. Neither univariate analysis nor the multivariate Cox proportional hazards model analysis showed prognostic value for gastric juice CA 19-9 and CEA positivities. CONCLUSIONS The gastric juice CA 19-9 and CEA levels have no diagnostic and prognostic significance in gastric carcinoma patients.