The science team grabbed 1 gold, 5 silvers, while the maths team clinched 2 golds, 3 silvers, and 1 bornze.
The outstanding students came from Hanoi-Amsterdam High School for Gifted Students, Cau Giay Secondary School, and Hanoi Star Secondary School.
Hoang Ngoc Bao Khue was also awarded Best Exploration in maths.
Vietnam is preparing well to host the 2019 competition.
Last year, the country took the top spot among 23 participating nations at the IMSO 2016 in terms of mathematics. Vietnamese students also carried off ten silver and three bronze medals in science.
IMSO is an annual competition in Math and Science for primary school students aged under 13, aiming to increase their interest in mathematics and sciences and to develop problem-solving skills.