Central nervous system (CNS) metastasis was noted in 309 patients of 1044 autopsy cases of breast carcinoma. The brain was involved in 193 cases, and cranial dura in 167 cases. In 82 cases, the cranial dura was the sole site of CNS involvement. Metastasis to the leptomeninges was found in 59 cases, and to the spinal cord and dura in 32 cases. Metastases to the infratentorial portion of the brain was almost as frequent as to the cerebrum. Forty-two percent of the brain metastasis were single lesions, which is similar to the frequency of solitary metastasis to the brain from malignant tumors as a whole. CNS metastasis occurred more frequently in younger patients than older patients, and the clinical course of these patients was shorter than for those patients without CNS metastasis. CNS metastasis developed in the late stage of the disease, and often was not recognized clinically. Only 31% of the cases were clinically diagnosed or suspected before death. A median survival of these patients after clinical diagnosis of CNS metastasis was 33 days. However, a significant improvement was noted in the clinical diagnosis and median survival in the latter half of the study period. Eleven patients lived for more than 1 year after diagnosis of CNS metastasis. Only 14% of the 309 patients died from CNS failure.