E‐cadherin is a calcium‐dependent cell–cell adhesion molecule expressed by melanocytes and responsible for their adhesion to keratinocytes in vitro. In this study, the expression of E‐cadherin and its associated cytoplasmic proteins α‐, β‐, and γ‐catenin was evaluated in melanocytic lesions by immunohistochemistry. E‐cadherin expression was evaluated in 70 malignant melanomas and the catenins in 35 of these specimens. Twenty benign melanocytic naevi were also evaluated for E‐cadherin and catenin expression. In normal epidermis, E‐cadherin/catenin immunostaining was localized at the intercellular borders. In melanomas, a differential loss of E‐cadherin expression was observed. Membranous E‐cadherin staining was absent in dermal nests of melanomas in their radial growth phase and in Clark level II and III lesions, whereas it was present in a high proportion of melanomas in their vertical growth phase, in Clark level IV and V lesions and in metastasizing melanomas. In contrast, superficial compartments of naevi showed membranous E‐cadherin immunoreactivity and junctional naevus cell nests displayed heterogeneous or diffuse cytoplasmic staining. Cytoplasmic α‐ and β‐catenin, but not γ‐catenin staining were detected in all benign and malignant lesions. These findings indicate that qualitative changes in the expression and cellular localization of E‐cadherin and of α‐, β‐, and γ‐catenin occur in melanocytic lesions and may reflect different stages in their progression. Copyright © 1998 John Wiley & Sons, Ltd.