Passengers flown by Aer Lingus in May topped the 1 million mark.
Overall numbers were up by 5.3% year on year with short-haul carryings rising by 3.7% to 914,000 and long-haul up by 20.2% to 107,000.
The short-haul load factor was up by 3.4 percentage points to 77.2% as capacity was trimmed by 1.8%.
The long-haul load factor was 84.4%, an increase of 2.9 points on May 2012, with capacity increasing by 16.8%.