According to the Ministry of Education and Training (MoET), the silver medal went to Le Thi Nguyet Hang from Danang while two bronze medals were presented to Pham Minh Duc from Nam Dinh and Le Xuan Luong from Hanoi.
Pham Thi Yen Ngoc from Thanh Hoa bagged the consolation prize.
The 26th IBO attracted 239 contestants from 63 countries and territories.
The organising board conferred 26 gold, 48 silver and 72 bronze medals and 24 consolation prizes on contestants.
China and the US topped the contest as all of their participating students won gold medals.
The 27th IBO will take place in Hanoi, Vietnam, from July 17-24, 2016.