The arrival of one of the most potent symbols of US capitalism in southern Ho Chi Minh City -- known as Saigon when American troops dramatically withdrew in 1975 -- is the result of a partnership with the son-in-law of Vietnam's powerful Prime Minister Nguyen Tan Dung.
McDonald's is following US rivals Burger King, KFC and coffee giant Starbucks into Vietnam -- a country many Americans associate more with an unpopular war than a newly wealthy middle class.
But with its 90 million-strong population and average per capita income of more than $1,500, "Vietnam is on the radar now" for US franchises, said Sean Ngo, managing director of consulting firm Vietnam Franchises Ltd.
Critics say that Vietnam's rapid economic growth since "Doi Moi" reforms opened up the country in the early 1990s masks rising inequality and inefficiencies in an economy still dominated by state-owned enterprises.
But signs of the country's rising affluence were on display today as hundreds of people queued at the McDonald's store on Ho Chi Minh City's Dien Bien Phu street -- named after the battle that forced the French to withdraw from their former colony Vietnam.
"I like fast-food. I don't like Vietnamese food. I don't like fish sauce," Nguyen Hoang Long, 25, told AFP as he devoured a Big Mac meal, referring to the pungent condiment made from fermented fish and sea salt that is used liberally in local cooking.
A Big Mac costs about USD 2.85 at the new outlet, while a bowl of traditional pho noodle soup can be bought on most street corners for around USD 1.50.
The arrival of McDonald's marks a full turnaround for the fortunes of US brands in former wartime foe Vietnam.
Iconic brands such as Coca-Cola were available in US-allied South Vietnam until the end of the war, but the companies pulled out after the communist victory which paved the way for the unification of the country in 1975.