Polish customs officials and border guards discovered and detained the group upon inspecting a truck in Budzisko, Gmina Szypliszki, in the country’s northeast, Poland in English reported.
They were all aged 14-38, and none had any document allowing them to enter Poland.
The truck's driver, a 51-year-old permanent Estonian resident, was also arrested and faces charges of assisting and organizing an illegal border crossing operation, for which he can be jailed for up to eight years.
The Vietnamese detainees will be deported to Lithuania, the report said.
Many illegal immigrants reportedly pay traffickers up to $15,000 to enter Poland in the hope of finding work in restaurants and markets, or to use it as an entrance to western Europe.