The two men – one in his early 50s and the other in his 60s – were both experienced pilots from Co Meath.
The bodies remained at the scene overnight – with Gardaí and the Coast Guard co-ordinating recovery efforts.
The light aircraft had taken off from Athboy Aerodrome in Co Meath and was heading towards Wexford in good weather conditions.
The alarm was raised by a hillwalker – who alerted emergency services after seeing the plane come down at Blackstairs Commons – near Mount Leinster on the Carlow/Wexford border.
There were no reports of any distress signal.
Both of the two men onboard – who are from Co Meath and aged in their 50s and 60s – were killed in the crash.
Their bodies remained at the mountainous and remote scene overnight – and Gardaí have been co-ordinating the recovery operation with South East Mountain Rescue and the Coast Guard helicopter.