The aim of our study was to evaluate the association between the expression of E-cadherin and clinical prognostic factors in uterine endometrioid adenocarcinoma of different histological grade. We have studied 104 postmenopausal women with diagnosis of endometrioid adenocarcinoma. We evaluated the presence of obesity and vaginal bleeding. Surgical specimens were fixed in 10% neutral buffered formalin solution and embedded in paraffin. 4 mm sections were stained by hematoxylin-eosin, von Gieson, and histological type of cancer, metastatic involvement of lymph nodes and depth of myometrial invasion were evaluated. Histological grade of cancer was assessed by FIGO grading system. All samples were analyzed by immunohistochemistry for E-cadherin (Dakocytomation). We assessed the number of E-cadherin-positive and negative tumor cells and degree of positivity (low, moderate, high). Histological study by hematoxylin-eosin has showed grade 1 endometrioid carcinoma in 35 cases (33.7%, group I), grade 2 adenocarcinoma in 44 cases (42.3%, group II), and grade 3 adenocarcinoma in 25 cases (24%, group III). Our results suggest that the loss of E-cadherin expression is associated with a higher histological grade of uterine endometrioid adenocarcinoma, depth of myometrial invasion, lymph node positivity, coexistence of obesity and vaginal bleeding. It seems that local invasion and metastatic spread of tumor should be preceded by the loss of E-cadherin expression in tumor cells, which progressively occurs in carcinogenesis. Therefore, E-cadherin negativity can be used as a poor prognostic factor and more aggressive chemotherapy regimen should be used.