Aer Lingus has reported a 2.5% drop in total passenger numbers - including Aer Lingus regional operations - to 868,000 for April.
The airline said the decrease is explained in part by the timing of Easter, which was at the end of March this year but in the first week of April in 2012.
Aer Lingus said that its short haul flown passengers fell by 3.3% to 784,000 while long haul passenger numbers increased by 6.3% to 84,000 during the month.
It said its load factor last month fell by 3.8 points to 68.9%. Aer Lingus said its short haul load factor stood at 68.7%, down 2.8 points, while its long haul load factor eased by 5.8 points to 69.3%.
For the year to date, the airline said its total passenger numbers are up 0.9% to 2.999 million compared to the same time last year.