It was reported that 36,371 units were sold among members of the Vietnam Automobile Manufacturers Association (VAMA) last month, down 0.51% from the previous month.
In the first 11 months, sales climbed 43% year-on-year to 369,334 units.
Truong Hai Auto Corporation (Thaco) led in the period with 123,140 units sold, up 38% year-on-year.
The company was followed by Toyota, with 81,491 units, and Mitsubishi, 36,805 units.
Honda and Ford rounded off the top five.
Last month automaker VinFast shipped its first batch of 999 electric cars to the U.S.
The company expects to sell 750,000 electric vehicles annually by 2026.