Birth family health history is shared with prospective adopters to help them understand a child's future health risks. But guidelines for health professionals indicate that such third-party information should not be shared without the consent of birth parents. In practice this can be difficult to achieve. Catherine Hill and Maria Edwards' survey of 57 adoptions sought to explore the views and experiences of adopters about the value of this information to both themselves and their child. Absence of information, particularly with respect to paternal history, was common and resulted in adverse consequences for children and an impoverished sense of identity. Adopters felt that lack of information also limited their understanding of the child and therefore their ability to offer therapeutic parenting; they were ‘parenting in the dark’. A majority expressed strong views that it was their child's right to have this information; a minority felt that confidentiality of birth family health information should remain a paramount consideration. These data furnish the debate with an important missing dimension from those whose lives are potentially enriched or impaired by the quality of information shared.