PURPOSE: To analyse the clinical and radiologic findings of brain metastasis of breast cancer. MATERIALS AND METHODS: Sixty-one of 1399 patients in whom breast cancer was diagnosed between 1983 and 1999 were affected by brain metastasis. Among these 1399, the stage of the breast cancer, in descending order of frequency, was IIA (n=508), I (n=366), IIB (n=247), IIIA (n=189), IIIB (n=45), 0 (n=33) and IV (n=11). The stage of the 61 brain metastases, similarly ordered, was IIB (12.5%), IIA (3.9%), IIIA (3.1%), IIIB (2.2%) and I (0.8%). In all confirmed breast cancers, the age distribution, in descending order of frequency, was 40 - 49years (n=610), 50 - 59 (n=301), 30 - 39 (n=291), 60 - 69 (n=124), 20 - 29 (n=41), 70 - 79 (n=28), and 80 - 89 (n=4). The age distribution of brain metastasis was 20 -29 (14.6%), 30 - 39 (7.9%), 50 - 59 (4.6%), 40-49 (2.6%) and 60 - 69 (1.6%). Imaging findings were available for 35 of the 61 patients affected by brain metastasis, and symptoms from brain among the 35, analysis of the symptoms of this metastasis, the site of the first distant metastasis to an extracranial or cranial organ, the interval from the diagnosis of breast cancer to brain metastasis, the interval from brain metastasis to death, and the difference in survival time between patients with initial and succeeding brain metastasis was undertaken. Brain CT findings were analysed in 29 cases and MRI findings in eight. RESULTS: The most common symptoms were headache and vomiting. Among the 35 brain metastasis patients for whom imaging findings were available, other systemic metastasis occurred in 22. Initial brain metastasis occurred in the remaining 13, and in seven of these there was also coincident organ metastasis, while six showed only brain metastasis. The most frequent intervals from the diagnosis of breast cancer to brain metastasis were 1 - 2 years(8/35) and 2 - 3years(8/35). Twenty-six of 35 patients died within one year of brain metastasis. Patients in whom this occurred later survived for longer than those in whom it occurred initially. According to CT or MRI, involvement was supratentorial (n=23), infratentorial (n=2) or at both sites (n=10). Twenty-four patients had multiple lesions and 11 had a single lesion. Precontrast CT imaging show the masses were isodense in 23 cases, hyperdense in three, hypodense in two, and calcified in one. In seven of eight patients who underwent MRI, the lesions showed iso signal intensity on T1WI and iso or high signal intensity on T2WI. The most common enhancement pattern was homogeneous nodular (n=20). CONCLUSION: Among breast cancer patients in whom metastis to the brain occurred, those in whom this happened later survived for longer than those in whom it took place initially. In order to delay brain metastasis and prolong survival, screening for the first distant metastasis is therefore important. The metastasis of breast cancer to the brain was mainly multiple. The most frequent location and postcontrast imaging findings were, respectively, the supratentorium and homogeneous nodular enhancement.