A case of malignant eccrine acrospiroma of the anterior chest wall is reported. This mass had been present for 20 years and during rescent 5 years it showed frequent ulceration and bleeding suggesting malignant transformation. Microscopically, several foci malignant transformation from preexisting benign eccrine acrospiroma are seen and in immunohistochemical staining, the tumor cells both benign and malignant portion, show positive reaction to cytokeratin.