Until the Warnock Report of 1984, the veil of secrecy surrounding donor assisted conception in the UK went more or less unchallenged. Starting with a look at the Report and subsequent legislation, Eric Blyth explores the main arguments for and against releasing information about their genetic origins to donor assisted offspring. Factors contributing to the debate include increasing public awareness of the importance of genetics in defining identity, the significant shift in attitudes towards openness in adoption which has taken place in England and Wales since the early 1990s and reluctance on the part of semen donors to be known to their offspring. Different attitudes in different parts of the world are also examined, as are the limitations of human rights legislation at both national and international levels.