The teenager's condition is described as "serious".
An investigation has been launched by Gardaí in Lucan as they search for new information regarding the serious assault of a 17-year-old man in Dublin on Monday morning.
The incident occurred at Rowlagh Gardens, Clondalkin in the early hours of 2 July.
It is understood the youth, who has not been named due to his age, sustained head injuries during an altercation which involved a group of people on the street outside a house in the housing estate at approximately 1am.
Following the altercation, the young man returned home only for his condition to worsen.
Emergency services were contacted and he was taken by ambulance to hospital. The teenager is currently being treated in Beaumont Hospital, where his condition is understood to be serious.
Gardaí have commenced an investigation and are appealing for anyone with information to contact them.
They are particularly appealing to anyone who may have witnessed anything at Rowlagh Gardens between 1am and 2am to contact the incident room at Lucan Garda Station on (01) 6667300 or the Garda Confidential line on 1800 666 111.
No arrests have been made to date and enquiries are ongoing.
