Tuna Vietnam, Nha Trang Bay and Phat Trien Seafood were the three biggest exporters, accounting for 64% of total shipments.
Exports of canned tuna jumped by 468%.
VASEP said declining fishing catches in South Korea and rising demand for canned products amid tightened spending drove up demand for Vietnamese products.
Vietnam was the eight biggest exporter of tuna to that country in the first half this year, but the largest seller of canned tuna, accounting for nearly 77% of all imports.