Aer Lingus made a profit of 60 million euro in the first nine months of the year, the company revealed.
The improving figures compare with a 34 million euro loss for 2009.
The carrier said changes in consumer behaviour had helped boost business with passengers leaving it later to book flights.
Christoph Mueller, Aer Lingus chief executive, said the returns were significantly better than last year but urged caution over the airline's prospects.
"Our performance in the third quarter and year to date is a very significant improvement on 2009 and strongly supports our strategy," he said.
"However, we remain cautious on the outlook for 2011 given concerns about the durability of the recent aviation sector performance as well as continuing economic uncertainty in our primary markets.
"I would like to express my appreciation to all our staff for the hard work and commitment applied in achieving this result."
The number of passengers flying on the airline has also grown 10% this year.
Aer Lingus is in the middle of a 97 million euro cost-cutting programme which reduced staff costs by nearly 20% this year.