The number of Irish 25 to 29-year-olds living at home has almost doubled in the last decade.
New Eurostat Data gives a figure of 68%, making Ireland an outlier within eastern Europe.
The figures also show young men are less likely to move out than young women.
Gill Hines, an education and parenting consultant says children are biologically ready to leave the home between the ages of 18 and 20, and there's a responsibility on parents to prepare their children to be self-managing.
She says there are impacts on all sides with parents often looking forward to seeing their adult children moving out.
"They sort of were looking forward sometimes to having their life back. You know, not having children be the center of their world.
"Of course, emotionally, they're always the center of your world, but being able to enjoy some time together and do some of the things that maybe they haven't been able to do for some years."