The N4 between Boyle and Ballinafad reopened at approximately 5pm Monday evening following a two car collision shortly after 9am Monday morning.
The collision took place close to the Horseman in the townland of Sheegorey.
One person was taken from the scene by air ambulance while another was brought by road ambulance to hospital.
The road remained closed until Monday evening for a forensic investigations.
North bound traffic was diverted at Boyle Celtic via the old Curlew road while south bound traffic was diverted via Corrigeenroe.