Passengers flown by low-cost carrier Wizz Air soared by 21% in January to more than 1.5 million.
The year-on-year rise came as the central and eastern European carrier increased capacity by 18.2% to 1.8 million seats.
The load factor was up by 1.9 percentage points to 83.5%.
Annual carryings for the 12 months to January were up by 21.7% to 19.4 million.
The airline announced 11 new routes last month covering Romania, Poland, Bulgaria and Hungary.