The crash happened at Brackbawn in Kilbehenny just after 3pm yesterday
Gardaí and emergency services attended the scene of the collision which involved a car and a pedestrian.
The pedestrian, a man in his 30s , was later taken to Cork University Hospital where his condition is currently described as critical.
The driver of the vehicle was uninjured.
An examination of the scene was conducted by Garda Forensic Collision Investigators and the road has since reopened.
Gardaí are appealing to anyone who may have witnessed this collision to come forward to them. In particular, any road users who were travelling in this area and who may have camera footage are asked to make it available to Gardaí.
Anyone with any information is asked to contact Fermoy Garda station on 025 82100, the Garda Confidential Line on 1800 666 111 or any Garda station.
