Germline BRCA1/2 mutations are more common in women with uterine serous carcinoma compared with the general population. The LOH and homologous recombination deficiency found in an USC of a BRCA1 germline carrier, support a causal relationship. Uterine serous carcinoma may be an overlooked component of BRCA1/2-associated hereditary breast and ovarian cancer syndrome. Screening for germline BRCA1/2 pathogenic mutations should be considered in women with uterine serous carcinoma.