Abstract: Conventional diagnostic methods used for pathologic nipple discharge (PND) include color ultrasound, mammary molybdenum target X-ray radiography (mammography), nipple cytologic smears, and ductography. Diagnosis of PND through inspection yields indirect signs and has low positive rate. Fiberoptic ductoscopy (FDS) allows direct visualization of intra-ductal lesions, evaluates etiology of PND, and accurately locates intraductal lesions through wire marking. FDS is a valuable test for the early diagnosis of breast cancer and can help identify appropriate location for surgical excision. Interventional treatment for ductal ectasia and inflammation is also efficient. Our study discusses FDS as a novel diagnosis and treatment method for PND patients.