The incidents took place in Tallaght and Drimnagh.
Two men have been seriously injured in separate collisions in Dublin overnight.
RTÉ reports that the first incident took place at 11pm last night on the Blessington Road in Tallaght, when a car collided with a 31-year-old pedestrian.
Emergency services attended the scene, and the man was taken to Tallaght Hospital for treatment. His injuries are said to be serious, but non-life-threatening.
The second incident occurred at 1:30am this morning on the Drimnagh Road in Dublin 12. The pedestrian, a man in his 40s, was seriously injured after being hit by a car. He was subsequently taken to Beaumont Hospital.
Local diversions are currently in place to allow for a technical examination.
Gardaí are now appealing for any witnesses to the incident to get in touch by calling Crumlin Garda Station on 01 6666200, the Garda Confidential Line on 1800 666111 or any Garda station.
