Ryanair has warned that full-year profits will be 12% lower than expected.
It is predicting the airline will make between €1.10bn and €1.20bn, instead of between of €1.25bn - €1.35bn, blaming a drop in passenger numbers because of pilot and cabin crew strikes in September.
The airline said forward bookings are down due to a fall in customer confidence because of a fear of further strikes also.
They have also claimed higher oil prices are a factor.
Ryanair’s Michael O’Leary said: “While we successfully managed five strikes by 25% of our Irish pilots this summer, two recent coordinated strikes by cabin crew and pilots across five EU countries has affected passenger numbers through flight cancellations, close in bookings and yields (as we re-accommodate disrupted passengers), and forward air fares into Q3.
"While we regret these disruptions, we have on both strike days operated over 90% of our schedule.
"However, customer confidence, forward bookings and Q3 fares have been affected, most notably over the October school mid-terms and Christmas, in those five countries where unnecessary strikes have been repeated."