Four cases of breast cancer with meningeal involvement are presented and a review of the literature is given. Post mortem examination of patients with malignant epithelial tumors shows meningeal carcinomatosis in less than 1%. In these solid tumors breast cancer is the most common primary site. The mode of tumor spread to the leptomeninges is not yet decisively known. Clinical symptoms and findings can be divided concerning three anatomic areas: cerebral, cranial nerve and spinal root. Slow onset of clinical symptoms and findings as well as their mixed pattern is generally noticed. Characteristic findings in cerebrospinal fluid are increased protein content, hypoglycorrhachia and identification of malignant cells. Other laboratory tests are generally of no diagnostic value. In some cases myelogram shows typical alterations. The value of computerized tomography in meningeal carcinomatosis remains to be solved. The following treatment for meningeal carcinomatosis by breast cancer can be recommended: Intrathecal methotrexate 0.2 mg/kg every 3 or 4 days until improvement of symptoms and laboratory findings in cerebrospinal fluid, followed by radiation of the clinically most involved areas and maintenance therapy with intrathecal methotrexate or systemic BCNU.