The 30 men and women, all Vietnamese, were found guilty of drug trafficking and given the death penalty while a further 59 defendants were handed sentences ranging up to life in prison, presiding judge Ngo Duc told AFP.
"This was Vietnam's largest ever trial in terms of defendants, the number of death penalties given out and the amount of heroin involved," Duc told AFP after the verdict was read out in the northern province of Quang Ninh - which borders China.
"Because of the large number of defendants and the seriousness of the case, the trial was held at the prison," Judge Duc added after the 17-day trial.
Investigators said the defendants belonged to four international smuggling rings responsible for trafficking heroin and other drugs from neighbouring Laos into Vietnam and China since 2006.
"All the defendants are Vietnamese and most of them came from Vietnam's northwestern provinces," court clerk Nguyen Trung Hieu told AFP.
