Gardaí attended the scene of a serious road traffic collision in Milltown yesterday evening.
Gardaí were alerted to the crash involving a bicycle and a truck at Russellstown at 5:30pm.
The cyclist, a man in his late teens, was taken to University Hospital Galway to be treated for his injuries.
He has since been transferred to Beaumont Hospital where his condition is described as serious.
The road was closed to allow for a technical examination to be conducted by Forensic Collision Investigators.
This has since concluded and the road has reopened.
Gardaí in Tuam are appealing for witnesses to come forward and to those with camera footage, including dash-cam, to make it available to them.
Anyone with information is asked to contact Tuam Garda Station on 093 708 40, the Garda Confidential Line on 1800 666 111, or any Garda Station.