Abstract Background: Professional societies recommend against the genetic testing of minors for hereditary cancer syndromes that present in adulthood. Yet, many adolescent specialists indicate that they would consider BRCA1/2 testing of minor children. We conducted interviews with parents who have had BRCA1/2 testing, to evaluate their opinions regarding the genetic testing of minors for BRCA1/2. Methods: 244 parents, including 67 BRCA1/2 mutation carriers (MCs), 140 parents with uninformative negative results (UN), 14 with true negative results (TN) & 23 with a variant of uncertain significance (VUS), from two cancer risk assessment programs completed semi-structured interviews. We used multiple logistic regressions to evaluate the associations among biomedical factors, demographic factors and support of testing minors. Wald tests and likelihood ratio tests were used to assess statistical significance for binary covariates and nominal covariates. Results: 38% of parents supported testing minors for BRCA1/2 in response to a dichotomous (Y/N) question. Support was greatest among parents with TN (64%) and UN (40%) results and lower among MCs (31%) and parents with a VUS (26%). In a multivariable analysis, support was greatest among parents who tested negative (p=0.02), were of minority race (p=0.06) and among fathers (<0.01). Responses to open-ended questions suggest that 27% of parents unconditionally support testing of minors, and 25% support testing only in certain situations. Psychological risks, a lack of medical necessity and the insufficient maturity of minors, were frequent concerns of those opposed. The potential to positively impact minors' health behaviors was the most reported reason for supporting testing. Conclusions: Up to 52% of parents who have undergone BRCA1/2 testing support pediatric testing for BRCA1/2. Given willingness among general and pediatric practitioners and interest among parents, further research is necessary to formally evaluate the risks and benefits of providing genetic testing to minors for adult-onset hereditary cancer syndromes in order to inform clinical practice and public policy that will ensure optimal psychosocial and medical outcomes for all members of families at risk for hereditary cancer. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4071.