The ministry had begun an investigation last September after Vietnamese sugar producers claimed they were hurt by the dumping of sugar imported from Thailand.
As many as 3,300 people lost their jobs with factories having to close. More than 93,200 farmers were affected.
The investigation found Thai sugar exporters had a dumping margin of 47.64 percent. In February, Vietnam had slapped preliminary anti-dumping and countervailing duty of 33.88 percent on sugar imported from Thailand.
Sugar imports from Thailand last year hit 1.3 million tons, a year-on-year surge of 330.4 percent, according to the preliminary investigation. The importsSugar imported from Thailand accounted for 90 percent of the total imports of the sweetener last year, according to the Food and Foodstuff Association of HCMC.