Nipple secretion is a common condition; it can occur in men and women, and be uni- or bilateral. It is related to hormonal changes, physical stimulation, intracerebral processes and certain drugs, and it is divided into three types: galactorrhoea, clear/bloody or viscous. Only the clear/bloody type is an indication of breast malignancy. Malignancy should always be ruled out in the presence of breast tumours. Treatment is determined by aetiology, and can vary from patient education, medications to surgery.