Breast cancer is the most common cancer in women. Germline mutations in BRCA-1 and BRCA-2 significantly increase the risk of developing breast and ovarian cancers, and are also associated with an increased incidence of primary cancers at other sites. We report the case of a 46-year-old woman previously treated for ductal adenocarcinoma of the breast with BRCA-1 who subsequently was diagnosed with multicentric glioblastoma multiforme (GBM) in the right temporal and right occipital lobes. We briefly discuss the incidence of BRCA-1 mutations in breast cancer as well as other primary neoplasms and consider potential mechanisms shared in the pathogenesis of breast and glial tumors.