Background: Syndecan-1 and B-catenin are cell adhesion molecules, which are expressed primarily on the surface of adult epithelial cells. The expressions of them have been appeared to be inversely correlated with tumor aggressiveness and invasiveness. Objective: The purpose of this study was to investigate the expression of syndecan-1 and B-catenin in tissue sections of the nodular and high-risk (micronodular and infiltrative type) basal cell carcinomas. Methods: Ten cases of nodular basal cell carcinoma and 10 cases of high-risk basal cell carcinoma (each 5 cases of micronodular and infiltrative type) were investigated. Specimens were assessed for syndecan-1 and B-catenin expression, using a semi-quantitative method in which the intensity of membranous staining was evaluated. Results: In a nodular basal cell carcinoma, syndecan-1 and B-catenin were expressed as similar intensity to normal epidermis. In high-risk basal cell carcinoma, syndecan-1 always showed decreased staining intensity relative to that showed in the normal skin. But, B-catenin showed similar to normal epidermis in the 5 cases, and decreased intensity relative to that of the normal epidermis in the rest. Conclusion: Our results suggest that the decreased expression of syndecan-1 and B-catenin in basal cell carcinoma is associated with the tumor aggressiveness. Especially, of the two adhesion molecules, syndecan-1 is more associated with the high-risk basal cell carcinoma.