The Adoption Authority of Ireland has called for the establishment of a national archive of information on adoptions "to honour and respect" the very sensitive and important historical information that exists.
Chief Executive Patricia Carey said that 48,000 people have been adopted in Ireland since 1953.
"If you multiply that up" there are half a million people in Ireland in some way affected by adoption, she said.
Speaking to RTÉ's Morning Ireland, she said that vast tracts of information on adoptions exists and "it is time we put that together in one place" in a national archive.
She said that with permission this information could be used for research.
The Adoption Authority of Ireland has released a special publication marking ten years of operation and has noted a number of changes in adoption in recent years.
Ms Carey said that children being adopted are now older or with additional needs and the Authority is working with a small number of countries to find families to work with those children and to parent them.
Ireland has worked extensively with the State Department in the US to develop a programme for adoptions, she said.
"Bespoke" adoptions are taking place, she said, where the US birth mother can choose Ireland as the place they would like their child to be adopted into.
Also, since 2005 over 15,000 people have joined a register of birth parents who wish to meet their children or share information.
Over 800 people have met or connected in some way.
Ms Carey said that "more and more in Ireland, people want to share information or meet and siblings who are keen to meet".
She said the stigma associated with adoption is a "myth" and Ireland has changed a lot in the last five to ten years.
Ms Carey said the Adoption Authority strongly recommends birth mothers or fathers to come forward if they would like to connect with their children.