A characteristic feature of malignant tumor is that they invade surrounding tissues and form metastasis. Alteration in cell adhesion mechanisms may contribute to invasion. We investigated for the expression of the epithelium-specific cell adhesion molecule E-cadherin in paraffin blocks of 42 squamous cell carcinomas of the head and neck. Among the 21 patients with lymph node metastasis, 11 patients did not show E-cadherin staining and 10 patients showed E-cadherin staining. Among the 21 patients without lymph node metastasis, only 2 patients did not show E-cadherin staining. We found that E-cadherin expression was inversely correlated woth the dedifferentiation of the tumor and lymph node metastasis. These data suggest that E-cadherin plays a important role in the progression of squamous cell carcinoma in the head and neck.