Expression of oncogene and anti-oncogene products in 12 cases of male breast carcinoma was studied. Positive staining was seen in 6 cases for c-myc, 6 cases for EGFR, 4 cases for c-erbB-2, 2 cases for N-ras, 5 cases for Rb and 3 cases for P53. One case was positive and 4 cases were negative for all above mentioned oncogene and antioncogcne products. In addition, Cathepsin D (Cath-D), ER, PR, AR, PCNA and AgNOR were also assayed. In all the cases showed c-erbB-2 or P53 positive were Cath-D positive. The significance of expression of c-erbB-2, c-myc, Cath-D, ER and PR in male breast carcinoma was emphatically discussed.