Liposarcoma of the male breast is rare. In English literature, nearly 90 tumors of this type can be found, but the majority of citation is female without detail descriptions of gross or microscopic features. Recently, we experienced a case with pleomorphic liposarcoma of the breast. This 62-year-old male patient presented with tumorous mass of right breast for 3 months ago. He underwent radical mastectomy under the impression of breast cancer. Received specimen was a breast and attached nodular bulging mass. The serial section reveal a relatively defined nodular mass consists of yellowish and glistened bulging tumorous lesion, measuring 5x4.5x5cm. Microscopically, there were multiple pleomorphic giant cells composed of plump esoinophilic or microvesiculated cytoplasm and bizarre nuclei with prominent nucleoli. These cells were positive staining for oil-red O. Ultrastructurally, variable sized numerous fatty vacuoles in the cytoplasm were seen.