Desmoplakin I and II are important components of the attachment plaque of the desmosome which mediates cell to cell adhesion, in epithelial cells. In this study we used well-characterized antibody against desmoplakin I and II immunohistochemically and immunoelectron microscopically on two cases of pemphigus vulgaris and one case of pemphigus erythematosus and two cases each of Hailey-Hailey's disease and Darier's disease. In the normal human epidermis the desmosomes were demonstrated in a dotted pattern along cell periphery. In pemphigus vulgaris and pemphigus erythematosus acantholytic cells and the perilesional cells exhibited normal dotted pattern along the cell periphery. In Hailey-Hailey's disease and Darier's disease, the dotted pattern is lost in acantholysed and perilesional areas and anti-desmoplakin I + II positive proteins were observed diffusely in the cytoplasm. Immunoelectron microscopical findings correspond to these light microscopical observations. It is concluded that in autoimmune acantholytic disease such as pemphigus vulgaris and pemphigus erythematosus, desmoplakins are intact even in acantholytic cells, whereas in genodermatoses such as vulgaris and pemphigus erythematosus, desmoplakins are intact even in acantholytic cells, whereas in genodermatoses such as Hailey-Hailey's disease and Darier's disease primary or secondary abnormalities abnormalities of desmosomes may be involved in their pathogenesis.