Of the figure, locally assembled cars totalled 3,439 units (down 61 percent) while imported vehicles numbered 841 (down 50 percent), according to the Vietnam Automobile Manufacturers' Association (VAMA).
VAMA members alone sold 3,679 vehicles last month, just half of January's figure.
The association attributed the fall to the high demand for vehicles in January ahead of the lunar New Year holiday and the low demand immediately afterwards. They added that February is a very short month, which also negatively affected the sales.
VAMA Chairman Laurent Charpentier acknowledged that two-month sales were down 1 percent from the previous year, but warned against undue pessimism.
Revenue in the first month of this year was extremely low due to an increase in registration fees introduced on January 1, he said.
Japanese Toyota retained its top position in sales last month, with 1,337 units sold, followed by Vietnamese carmaker Truong Hai.
Ford Vietnam ranked third, but retail sales rose more than 63 percent year-on-year to 351 vehicles, the highest increase recorded by any carmaker.
Its strong February performance allowed Ford to capture 8.3 percent of the overall vehicle market for the month.
VAMA has projected that overall car sales this year will rise 8 percent from 2012 to about 100,000 units.