Risk-reducing salpingo-oophorectomy is currently advocated for the reduction of both breast and ovarian cancer risk in BRCA1/2 carriers, but residual risk of peritoneal primary cancer remains a concern. A sequential series of women attending a single institution for ovarian risk management underwent either risk-reducing surgery or screening. A person-years at risk analysis was used to compare observed versus expected cancers. In total, 300 women underwent risk-reducing salpingo-oophorectomy, including 160 BRCA1/2 mutation carriers. Three occult ovarian cancers were detected at surgery. There have been 2400.4 years of follow-up and 15.79 expected cancers. No peritoneal cancers have occurred. Amongst 503 women controls with 3444.3 years of follow-up, 15.93 ovarian cancers were expected and 17 were found. There were six ovarian cancer-related deaths in the control group compared with one in the surgery group. Risk-reducing salpingo-oophorectomy in a single institution has so far avoided peritoneal cancer incidence.