Gardai are investigating after a man was found with serious injuries in the city last night.
The man in his 30s was found by a passer by at around 8.15pm on Firhouse Road.
He was taken to Tallaght Hospital where he remains in a serious condition.
At this stage Gardaí believe the man may have received his injuries accidentally, as a result of a fall.
A witness appeal has been launched.
Gardaí particularly want to speak to a woman, described as in her late 30s or early 40s, who stopped at the scene to help but left before Gardaí arrived.