In this study, 26 cases of nonpalpable breast cancer with nipple discharge treated at our department were reviewed. Their discharge was either bloody or serous with a positive hematest, but all except for one were negative for cytology, while CEA value of the discharge was high in 72.7%. Mammograms were found to be unreliable for diagnosis, while abnormal findings were observed in 84.6% by ductography. However, final diagnosis was determined histopathologically from surgical specimens, showing 14 intraductal and 12 invasive ductal cancers, none with components of comedo carcinomas. Seventeen patients underwent mastectomy following duct-lobular segmentectomy and a small remnant of intraductal carcinoma was found microscopically in only one patient. All patients except for one have survived for 98 months on average with no symptoms of metastasis. These findings suggest that duct-lobular segmentectomy with an adequate surgical margin should be adopted as the final operation for selected patients with nonpalpable breast cancer involving nipple discharge.