The Commission to Inquire into Child Abuse has spent nine years looking into allegations from thousands of former pupils of state schools and orphanages, some which date back more than 60 years.
It is due on Wednesday while a second report looking into how sex abuse complaints were handled by the Catholic Church will be published by the commission in the summer.
It is thought that some 500 priests have been implicated in the abuse allegations.
Many thousands of children suffered at the hands of religious orders such as the Christian Brothers and Sisters of Mercy at industrial schools and orphanages. Most of the children were born outside wedlock or came from large impoverished families that could not afford to feed them.
The commission was founded in 2000 following a documentary for Irish television which claimed there was widespread sexual, physical and emotional abuse within Catholic institutions.
Mary Raffety, who produced the programme said the abuse suffered was "way off the scale" and "designed to break children".
At Easter, the Archbishop of Dublin, Diarmuid Martin, said the report would "shock us all".