The findings followed a four-day appellate trial.
One of the appellants, Nong Van Len had his death sentence reduced to a life sentence at the June 19 hearing.
The trial was presented with evidence of 5,000 cakes of heroin weighing a total of 1,750 kilos, plus thousands of methamphetamine pills.
Of a total of 89 defendants at the preliminary hearing held in January, the provincial People's Court handed down the death penalty to 30 of the traffickers, gave life imprisonment to 13 and up to 20 years in jail for many others.
They were charged with drug trafficking, forging documents and hiding military weapons. They were also convicted of doing illegal business, not denouncing criminals, bribing and being involved in bribery.
Of the 89 defendants, 40 appealed for a reduction in their sentences, one requested a review of his charges, and another continued to plead his innocence.
The court affirmed life imprisonment sentences handed down to four defendants and from four to 20 years in jail for another four.
The crimes were discovered late last year. Police said it involved a trafficking ring set up in Vietnam and involving Laos and China.
