Review of the case notes of 660 patients with a diagnosis of breast cancer during a five-year period showed that in 119 cases there had been thoracic metastases. These were recorded as pleural or extrapleural metastases (79 patients), mediastinal tumour (46 patients), lymphangitic carcinoma (41 patients), pulmonary nodules (34 patients), and solitary pulmonary nodule (nine patients). Endobronchial metastases were present in seven patients and multiple pulmonary tumour emboli in two. The thorax was often the initial site of tumour recurrence. Most of these recurrences were present in several locations (intrathoracic or both intrathoracic and extrathoracic) simultaneously, facilitating the clinical diagnosis of metastatic breast cancer. Histopathological confirmation of metastasis was mandatory for the 10 patients who had a solitary intrathoracic abnormality without evidence of disease elsewhere. The median survival after diagnosis and treatment of a solitary thoracic metastasis was 42+ months and three of 10 patients are currently in remission (at 44, 87, and 121 months). The small tumour burden and early diagnosis giving lead time may explain the long survival in this group of patients.