The three gold medals went to Nguyen The Toan from Hanoi, Tran Hong Quan from Thai Binh and Pham Tuan Huy from Ho Chi Minh City.
Vuong Nguyen Thuy Duong from Danang and Ho Quoc Dang Hung from Ho Chi Minh City earned silver medals while Nguyen Huy Tung from Haiphong got a bronze medal.
The 55th IOM held in South Africa from July 3 to 13 attracted 560 contestants from 101 countries and territories.
Vietnam ranked in 10th place with 159 points, after China, the US, Taiwan, Russia, Japan, Ukraine, the Republic of Korea, Singapore and Canada.
Vietnam was down in three notches from last year’s ranking.