Objective: To ascertain the perspectives of parents of children conceived via oocyte donation regarding donor anonymity and disclosure of the nature of their conception to their children. Methods: Information was gathered by means of an anonymous online survey initiated by the Donor Sibling Registry, in which 108 parents with 143 children conceived following oocyte donation and aged between one year and 15 years participated. Results: Parental use of an anonymous or open-identity donor-and regardless of parental choice of donor-makes very little difference to the timing of parental disclosure to their donor-conceived child about their conception. The median age of children at disclosure is about 3.5 years; UK/Australian parents seem more ready to tell their children at an early stage (median age around two years) than North American parents (median age around 4.5 years), although about three quarters of all children have been told by the age of six years. Considerable ambiguity among parents who intend to disclose to their children as to the optimal age of disclosure is evidenced. Conclusions: Parents' experiences of disclosure to children at different ages need to be more thoroughly examined in order to establish a coherent body of knowledge that may facilitate improved evidence-based parental decision making.