The surplus in the same period last year was $0.6 billion.
But exports fell in November by 8.4% to $29.18 billion, which took the full-year figure to $342.21 billion.
The U.S. has been Vietnam’s biggest export market ($101.5 billion).
Meanwhile, imports were worth $331.61 billion, a year-on-year increase of 10.1%.
They included shipments of $109.9 billion from China, the biggest exporter to Vietnam.
Last year exports had been worth $336.31 billion, up 19%, and imports, $332.23 billion, up 26.5%, for a trade surplus of $4.08 billion.
The surplus has been growing since 2016, according to the GSO.