The number of passengers serviced by the Sofia Airport rose by an annual 3.0% to 291,272 in April, the airport said.
Passengers on regular international routes reached almost 270,000 in April, the airport said in a statement on Wednesday.
The traffic on domestic routes started to stabilize last month after the Varna airport, which was temporarily closed for an upgrade, restarted operations.
A total of 3,652 aircraft took off and landed at the Sofia Airport in April, 5.7% less than a year earlier.
The volume of cargo and postal shipments rose by an annual 2.2% to 1,282 tonnes in the period under review.