The metastasis of extra-mammary malignancy to breast is extremely rare; literature reports the incidence between 0.4-1.3%. Primary sites include the contralateral breast, leukaemia, lymphoma, malignant melanoma, sarcoma, lung, prostate, ovary, colon and the stomach. Here we present a rare case in which lung cancer was found to metastasise to the breast. Initially the patient presented with chest symptoms and a left breast lump was detected clinically. The radiological and histological investigations confirmed the diagnosis of primary lung cancer with breast metastases. Prognosis of such cases is generally poor.