A YouTube video shows young women in open vests and red bikini tops gyrating in the aisle as gleeful male passengers snap photographs on the Vietjet Air flight.
State-run media reported Vietnam's Civil Aviation Administration fined the airline 20 million dong ($960) for staging the three-minute show without receiving official approval.
In a letter to Vietnamese authorities Tuesday, the company said the event inaugurated its first flight from Ho Chi Minh City to coastal Nha Trang. It said all safety regulations were followed. A company spokeswoman refused to comment on the fine.
Vietjet Air was founded in 2007 and is privately owned.