The men were caught in northern Cao Bang province on the border with China with nearly 100 kilograms (220 pounds) of heroin from Laos in their truck, state-run Thanh Nien newspaper reported.
Vietnam is a key trafficking hub for narcotics from the "Golden Triangle" covering Laos, Thailand and Myanmar, one of the world's largest drug producing regions, and the latest bust is one of the largest in Vietnam in recent months.
Photos on state media showed the alleged ringleader, 31-year-old Tran Van Bang, standing with a large pile of heroin bricks.
The bust follows a similar seizure last month in northern Vietnam, where police confiscated 170 kilograms of heroin worth $3 million also from Laos, reportedly the largest-ever drug haul in the one-party state.
Authoritarian Vietnam has some of the toughest drug laws in the world. Anyone caught with more than 600 grams (21 ounces) of heroin or more than 20 kilograms of opium could face the death penalty.