The aim of this study was to evaluate the pattern of p63 expression and its implication in secretory carcinoma of the breast. Immunohistochemical staining for p63, p53, MDM2, and smooth muscle actin was performed in 7 cases of secretory carcinomas. Nuclear expression of p63 was observed in 3 cases, whereas staining against cytoplasmic and intraluminal secretory material were observed in 4 cases. p53 was expressed in 3 cases and MDM2 in 2 cases. The loss of myoepithelial cells was confirmed by immunohistochemical stain for smooth muscle actin in invasive secretory carcinomas. The pattern of expression of p63 in secretory carcinoma of the breast was revealed in nuclei or cytoplasm/secretory materials.