The company has invested $4 million on equipment and 125 new staff at Dulles after being awarded a three-year contract by the Lufthansa Group.
As a result, it will provide ground and passenger handling services as well as aircraft cleaning and de-icing services for Lufthansa, Swiss International Air Lines, Austrian Airlines and Brussels Airlines, which between them operate a total of six flights a day at the US gateway.
The new contract means that dnata now serves 14 airlines with a team of over 300 customer-oriented staff at IAD, managing 5,200 aircraft movements annually.
David Barker, CEO of dnata USA, said: "We are delighted to expand our long-standing partnership with Lufthansa Group at Washington Dulles.
"The airlines of Lufthansa Group all share our passion for safety, quality and service excellence, and we are proud to be their ground handler of choice at nine airports in the United States.
"We keep investing in our team, infrastructure and equipment to cement our leading position and continually provide the best possible services to all of our over 60 airline customers in the world's largest aviation market."