Background & Aims: The E-cadherin-catenin complex plays a critical role in the maintenance of normal tissue architecture, Mutation of any of its components is believed to result in loss of cell-cell adhesion and contribute to neoplasia, The aim of this study was to examine the expression of E-cadherin and alpha-, gamma-, and gamma-catenin ire gastric carcinoma and dysplasia and determine any relationship with tumor characteristics and survival, Methods: Immunoperoxidase staining of E-cadherin and alpha-, beta-, and gamma-catenin was performed using 89 gastric carcinomas, lymph node metastases, and gastric biopsy specimens from 24 patients with dysplasia and 10 healthy controls, Results: Membranous staining was observed in control biopsy specimens for all components of the complex. Up to 57% of gastric dysplasia and 90% of tumors stained abnormally for one or more components of the cadherin-catenin complex, Abnormal E-cadherin and gamma-catenin staining occurred more frequently in diffuse than intestinal tumors (P < 0.0005 and < 0.05, respectively). No association with tumor grade or stage was found, A survival advantage was noted in intestinal and diffuse tumors retaining membranous expression of beta-catenin, independent of tumor type, grade, or stage (P < 0.005), Conclusions: Abnormal expression of the E-cadherin-catenin complex occurs frequently in gastric carcinoma, The close correlation with poor survival suggests that abnormal beta-catenin may be a useful prognostic marker.