Bangkok's Suvarnabhumi airport posted a 14.3% rise in passenger traffic in May to 4.14 million.
The airport's international passenger traffic increased by 9.14% to 3.15 million, while its domestic passenger traffic rose by 34.9% to 985,000, operator Airports of Thailand (AOT) said in a statement.
The total amount of cargo handled by the airport increased by 8.82% to 121,000t.
Apart from Bangkok's Suvarnabhumi and Don Mueang airports, AOT operates airports in Chiang Mai, Chiang Rai, Phuket and Hat Yai.
Total passenger traffic at all six airports grew by 11.6% to 5.61 million in May. International passenger traffic increased by 9.54% to 3.51 million and domestic passenger traffic rose by 15.2% to 2.01 million.
Cargo volumes at the six airports rose by 8.8% to 127,000t, AOT added.