Male breast carcinoma is a rare neoplasm, accounting for fewer than 1% of all malignancies of the breast. We report the case of a 65-year-old man who presented at our institution with a lump in his left breast. Histologically, the tumour had marked nuclear pleomorphism and contained multinucleated giant cells. Immunohistochemical staining demonstrated that the tumour cells were positive for cytokeratin AE1/AE3, E-cadherin, p53, Ki-67, cyclin D1, estrogen and progesterone receptor proteins, but negative for c-ERB-B2 and CD68. Based on the latest World Health Organization classification, the tumour was diagnosed as pleomorphic ductal carcinoma of the breast. To the Authors' knowledge, this is the first case report of pleomorphic carcinoma of male breast.