Objective: To explore the clinicopathologic features of secretory carcinoma of breast (SCB). Methods: Four cases of SCB were analyzed by light microscopy, histochemistry, immunohistochemistry and electron microscopy. The clinical data were also analyzed. Special staining of periodic acid-Schiff reaction with diastase pretreatment, immunohistochemical staining of ER, PR, HER-2, p53, MIB-1, S-100, p63, CK8/18 and EMA by En Vision method were performed. Results: Solid, cfibfiform, tubular, or papillary architecture may be seen. Tumor forms cystic spaces filled with abundant pale pink secretory material, positive with diastase resistant periodic acid-Schiff (PAS-DR) stains. Tumor calls were small with bland nuclei and abundant pale, eosinophilic cytoplasm, rare mitotic activity and necrosis. ImmunohistochemicaUy, tumor calls were positive for CK8/18, EMA, negative for S-100, p63 and variable partially positive for p53, ER, PR, HER-2 and MIB-1. Under electron microscopy, the tumor cells possessed numerous membrane-bound secretory vacuoles in cytoplasm lined by microvilli. Con-clusion: SCB is a rare, low-malignant neoplasm. SCB have pathology, clinical picture, treatment, follow-up, immunohisto-chemical and genetic features that distinguish them from invasive ductal carcinomas of the usual type.