BRCA1/2 carriers have a higher risk of developing breast and ovarian cancer at a younger age. Preimplantation genetic diagnosis (PGD) and prenatal diagnosis (PND) are two of the few options available to avoid transmitting the mutation. To inform the bioethics debate about authorization, a contingent valuation survey elicited preferences regarding access to PGD and PND from a sample of 460 unaffected by cancer BRCA1/2 carriers (GENEPSO cohort). We find that the respondents can be classified into three groups: one opposed to PGD/PND (28.3%), one strongly in favour of PGD/PND (45.8%), and one in an intermediate position (25.9%). We look for the determinants of these preferences, especially of the willingness to pay for PGD/PND. Overall, we find that BRCA1/2 carriers support access to PGD/PND, which has implications for recommendations to decision-makers.