Nok Air has launched two daily flights between Bangkok and Hanoi on November 1 using its new 190-seater Boeing 737-800.
The aircraft has enhanced comfort and entertainment, said its CEO Patee Sarasin.
"We also look forward to bring Vietnamese travellers to fully enjoy our Thai hospitality," he said.
The Boeing comes with a new interior design, larger windows and enhanced fuel efficiency.
Meanwhile, the airline has launched two daily flights from Don Muang Airport to Chiang Rai and Ubon Ratchathani using the 168-seater Boeing 737-400.
To promote the new flights, Nok Air is offering a special "three-baht-a-seat" promotion. The price excludes airport tax, insurance, fuel surcharge and VAT.