The development board for the new National Children's Hospital has said the hospital will take its first patients by the second quarter of 2019.
The hospital will be built on the St James's Hospital site in Dublin 8.
International architects BDP have been appointed to design the new hospital by next summer.
The aim is to secure planning permission by December 2015 and for building work to begin in January 2016.
The board said it plans to take its first patients by the summer of 2019.
Around 2,300 staff will work at the new facility, which will have nearly 390 beds for patients.
Chairman of the board Tom Costello said that work has to be done on access and car parking for the new hospital.
Families with sick children and staff will be guaranteed parking at the new hospital.
Booking of spaces in advance will also be provided for, with around 1,000 spaces set to be available at the hospital.
Minister for Health Leo Varadkar said the decision about the location for the new hospital has been made.
He said that while he cannot presume the view of An Bord Pleanála, he believed that planning permission will be granted, as there have been extensive consultations with the body.
The St James's site was chosen in November 2012 after initial plans for the Mater Hospital were rejected.
