The driver of the second vehicle has been taken to hospital
Gardaí are appealing for witnesses to a fatal collision in Co Monaghan.
It happened shortly before 5.00pm Wednesday on the N2 between Castleblaney and Carrickmacross.
The collision involved a car and an articulated lorry.
The driver of the car, a man believed to be in his 70s, was pronounced dead at the scene.
The driver of the lorry was taken by ambulance to hospital - but his injuries are not thought to be life-threatening.
The road has been closed to traffic in both directions as gardaí and emergency services examine the crash site.
Local diversions are in place.
Anyone with information is asked to contact Carrickmacross garda station on 042-969-0190 or the Garda Confidential Line at 1800-666-111.