Premenopausal risk-reducing salpingo-oophorectomy (RRSO) in BRCA1/2 mutation carriers effectively reduces ovarian cancer risk, but also reduces breast cancer risk. Breast cancer risk reductions up to 50% have been reported for both BRCA1 and BRCA2 mutation carriers, but recent prospective studies were not able to reproduce this finding for BRCA1 mutation carriers. Breast cancer incidence after RRSO was assessed in a consecutive series of 104 BRCA1 and 58 BRCA2 mutation carriers. On the basis of data from our own centre, and assuming a 50% risk reduction through RRSO at premenopausal age, we expected to find 8 breast cancers (range 6-10) in this population for the reported screening period (532 women-years). In 162 carriers with a median age of 41 years at RRSO, 13 incident breast cancers were diagnosed. In BRCA1 mutation carriers, 12 incident breast cancers were found compared with 5 (range 3-6) expected and in BRCA2 mutation carriers 1 breast cancer was found compared with 3 (range 2-5) expected. Breast cancer incidence after premenopausal RRSO is still high, especially in BRCA1 mutation carriers. Previously reported breast cancer risk reductions up to 50% were not confirmed. As a consequence, continued intensive screening for breast cancer is warranted in BRCA1 and BRCA2 mutation carriers after RRSO.