Out of the 18 homes examined by the Commission of Investigation, 9,000 children died.
56 thousand unmarried mothers - ranging in age from 12 years old to women in their 40s - along with 57 thousand children lived in the institutions.
The Commission says women who gave birth outside marriage were subjected to "particularly harsh treatment" in the period looked at from 1922 to 1998.
It found that was "supported by, contributed to, and condoned by" the institutions of the State and the Churches.
Taoiseach Michael Martin says the report makes often harrowing reading.
The Children's Minister says Mother and Baby Homes were places of callousness, brutality and shame.
Roderic O'Gorman says the death rate was truly shocking.