The immunohistochemical expression of E-cadherin (E-CD) was correlated to differentiation grade, tumor size, axillary lymph node metastasis, hormone receptor status and disease outcome in 230 infiltrating ductal breast carcinomas. E-CD expression was reduced in 116 tumors (50.4%). Reduced E-CD expression was more frequently found in high histological grade and progesterone receptor negative tumors. In contrast, preserved E-CD expression was more frequently observed in tumors with axillary lymph node metastasis, particularly in the group of patients with 1 to 3 positive lymph nodes. A weak association between reduced E-CD expression and shortened overall survival was found in univariate survival analysis, that was lost when the patients were adjusted for other pathological factors in multivariate analysis. These data indicate that E-CD may be considered a differentiation marker in ductal carcinomas of non special type. However, the relationship between E-CD expression and lymph node metastasis and disease outcome remains to be established.