Inherited mutations in BRCA1 or BRCA2 (BRCA1/2) confer very high risk of breast and ovarian cancers. Genetic testing and counseling can reduce risk and death from these cancers if appropriate preventive strategies are applied, including risk-reducing salpingo-oophorectomy (RRSO) or risk-reducing mastectomy (RRM). However, some women who might benefit from these interventions do not take full advantage of them. We evaluated RRSO and RRM use in a prospective cohort of 1,499 women with inherited BRCA1/2 mutations from 20 centers who enrolled in the study without prior cancer or RRSO or RRM and were followed forward for the occurrence of these events. We estimated the age-specific usage of RRSO/RRM in this cohort using Kaplan-Meier analyses. Use of RRSO was 45% for BRCA1 and 34% for BRCA2 by age 40, and 86% for BRCA1 and 71% for BRCA2 by age 50. RRM usage was estimated to be 46% by age 70 in both BRCA1 and BRCA2 carriers. BRCA1 mutation carriers underwent RRSO more frequently than BRCA2 mutation carriers overall, but the uptake of RRSO in BRCA2 was similar after mutation testing and in women born since 1960. RRM uptake was similar for both BRCA1 and BRCA2. Childbearing influenced the use of RRSO and RRM in both BRCA1 and BRCA2. Uptake of RRSO is high, but some women are still diagnosed with ovarian cancer before undergoing RRSO. This suggests that research is needed to understand the optimal timing of RRSO to maximize risk reduction and limit potential adverse consequences of RRSO.