The ship has also been coordinating other rescue efforts
The Defence Forces say the Irish vessel LÉ Eithne has rescued 346 migrants off the Libyan coast.
At 8.00am Friday morning, the ship located and rescued a total of 135 migrants from an inflatable craft north west of Tripoli.
This followed a request from the Italian Maritime Rescue Co-Ordination Centre.
The LÉ Eithne was then sent to coordinate rescue efforts of three NGO vessels, dealing with 10 platforms in distress (PIDs).
The Irish vessel has now completed a second and third rescue of 211 migrants from two further inflatable craft, as well as taking 85 migrants on board from one of the other ships.
The LÉ Eithne currently has 431 migrants on board - 346 rescued, 85 transferred from an NGO vessel - and is proceeding to two further PIDs.
The migrants on board are currently receiving food, water and medical treatment.
The Eithne was deployed to the Mediterranean on May 23rd as part of the Government's response to the migrant crisis in Europe.
Since it was first deployed with Operation PONTUS in May 2015, Defence Forces personnel have rescued 15,621 migrants.