Mammary ductoscopy is a modern, minimally invasive procedure that enables direct, in vivo observation of the mammary ductal system, primarily by nipple discharge. The rapidly developing device is suitable for aimed biopsy for further cytological or molecular examinations. High-tech equipments facilitate polypectomy or laser vaporization of certain intraluminal lesions, and play an important role in the direct surgical excision of the duct or the so-called terminal duct-lobular unit. The above listed facilitate the early diagnosis of malignancies even before imaging could detect them, and the control of high risk patients. Ductoscopy can foster surgical removal of ductal in situ tumors as anatomical units, thus enabling the optimization of radicality of breast conserving surgeries. Authors give a detailed description of the surgical techniques, and provide a wide review of the literature, for the first time in the Hungarian language. Orv. Hetil., 2011, 152, 1284-1293.