Motorists have been asked to avoid the stretch of road on the M50 southbound near Junction 12 due to an overturned truck.
The truck was carrying a number of horses inside.
The incident occurred at around 6.30pm this evening.
Emergency services remain at the scene.
The driver of the truck was uninjured in the incident.
Gardaí have said all five horses invovled are in good health. One was treated for injuries at the scene by a vet.
A horsebox is on route for them to be taken away from the scene.
The stretch is expected to remain closed until a crane arrives to remove the overturned truck.
AA Roadwatch has advised motorists to exit the motorway at J10 Ballymount or J11 Tallaght.
#M50 Southbound closed J12 Firhouse to J13 Ballinteer after a truck overturned. Recovery ongoing by @M50Dublin with @GardaTraffic, we hope to get everybody moving again. Rubberneckers affecting Northbound traffic @aaroadwatch @DCCTraffic #Dublin #fire #traffic pic.twitter.com/sD3C1MNOwA
— Dublin Fire Brigade (@DubFireBrigade) July 21, 2018