The four men pleaded guilty to playing different roles in a $2.8 million cannabis operation in Australia.
Tuan Dac Trinh, 38, and Kim Phuong, 50, were found guilty of "cultivating a large commercial quantity of a prohibited plant" and sentenced to three years and four months each, The Herald reported.
Vuong Luu Quoc, 27, was jailed for two and a half years while 26-year-old Anh Quang Pham got two years and three months.
Australian police officers arrested the Vietnamese gang in February 2017 after hundreds of cannabis plants were found in six separate homes in the suburbs of Maitland, New South Wales, during multiple raids in the area.
The four suspects admitted in a court in October last year to "crop sitting" the cannabis plants at homes in Tenambit, Heddon Greta and Morpeth. Crop sitting refers to the act of living inside homes while watering and keeping watch on cannabis plants grown there.
Quoc and Trinh were illegal immigrants in Australia. They could be deported to Vietnam after serving their sentences, the report said.
It is a crime to be caught with cannabis in Australia. However, possession of a small amount for personal use is not a criminal offense in several states.
The Australian government estimates more than 2,300 Vietnamese students have overstayed their visas in the country. Many of them have been involved in growing and selling cannabis.