Approximately 100 female secretory carcinoma cases have been reported. Although this tumor was initially termed juvenile carcinoma as the patients were all children and adolescent females, subsequent reports demonstrated that it occurs in females of all ages. Moreover, to date, only five males with this tumor have been reported. As with the initial female secretory carcinoma cases, all five were children or young adults. A very rare case of non-invasive secretory carcinoma of the breast arising in a 51-year-old Japanese male is described. He presented with a lump in his left breast. The surgically resected tumor was a typical secretory carcinoma histologically, except that there was no infiltration of the surrounding stroma, and was composed of tumor cells with vacuolated cytoplasm that contained secretory materials. This case, the first recorded secretory carcinoma of the breast in a middle-aged male, demonstrates that this tumor may also arise in mature males, as is the case in females. Physicians should not rule out the possibility of a secretory carcinoma of the breast regardless of patient age and gender.