Aim: To measure weight gain among unaffected women with a BRCA1 or BRCA2 mutation after undergoing an oophorectomy. Patients & methods: We compared the bodyweight of women with (n = 405) and without an oophorectomy (n = 741) at baseline as well as the rate of weight change prior to and following surgery among 1454 BRCA mutation carriers who had an oophorectomy. Results: There was a small and non-significant difference in bodyweight between BRCA mutation carriers who had an oophorectomy compared with those women who did not (151.5 vs 149.1 pounds; p = 0.26). There was an increase in bodyweight with increasing age, but this relationship did not differ prior to and following surgery (p comparing the slope parameters = 0.78). Conclusion: Oophorectomy is not associated with significant weight gain in high-risk women.