Cell adhesion molecules, such as epithelial cadherin (E-cadherin), might be involved in the processes of tumor invasion and differentiation. The aim of this study was to investigate the expression of E-cadherin, α-catenin, and β-catenin in endometrial carcinoma and to determine the prognostic value of these factors. We have investigated the expression of E-cadherin, α-catenin, and β-catenin by immunohistochemistry in 225 endometrial carcinomas. The correlation between the E-cadherin and the catenins and their correlation with several histologic and clinical parameters were analyzed. Negative E-cadherin, α-catenin, and β-catenin expression was observed in 44%, 47%, and 33% of endometrial carcinomas, respectively, and was correlated with histologic FIGO grade 3 (P < 0.001). Negative E-cadherin expression was more often observed in nonendometrioid endometrial carcinomas (NEECs) than in endometrioid carcinomas (75% versus 43%; P = 0.04). Combined positive E-cadherin, α-catenin, and β-catenin expression was an independent positive prognostic factor for survival in patients with grade 1–2 carcinomas (P = 0.02). Negative E-cadherin expression was found to be associated with histologic grade 3 and with NEEC. Combined positive E-cadherin, α-catenin, and β-catenin expression was a significant prognostic factor.