In the Nottingham Breast Clinic 5000 new cases are seen annually; 3000 are sent because the general practitioner believes that he/she has found a lump. It is the diagnosis and management of this common problem that is considered in this chapter. The traditional management of the palpable breast lump included excision to establish accurate diagnosis; indeed up until 20 years ago even simple cysts were excised. Now most surgeons accept that a woman with no residual palpable abnormality after aspiration of blood-free fluid from a cyst requires no further treatment. Most solid breast lumps are benign on histological examination; their routine removal a mistake in judgement. The challenge in the management of a palpable lesion is to correctly diagnose all the cancers without having to remove those which are benign, unless the patient wishes.