<h4>Importance</h4>Long-term follow-up studies regarding the safety of risk-reducing mastectomy (RRM) in terms of cancer risk and surgical complications among women with germline pathogenic variants (gPVs) in BRCA1 or BRCA2 (BRCA1/2) are scarce.<h4>Objective</h4>To analyze cancer risk and surgical complications after RRM.<h4>Design, setting, and participants</h4>This nationwide cohort study investigated 1208 Swedish women with a confirmed gPV in BRCA1/2 without previous breast cancer identified through the Swedish Cancer Genetic Units between March 31, 1994, and January 2, 2019. Here, BRCA1 is linked to breast cancer.