Dmitri Shedko, 33, was detained by police of Phan Thiet after planting dozens of cannabis plants inside a bedroom of a rented house in the city.
On Friday, police searched the house and found 27 cannabis plants under cultivation.
Three kilograms of dried cannabis was also found, along with equipment used to plant and grow cannabis.
Shedko said he purchased seeds and other planting equipment two months prior. After harvesting and processing, he distributed the cannabis to his Russian friends in Mui Ne and Phan Thiet.
Cannabis is on the list of narcotics forbidden in Vietnam. Those growing cannabis in small scale could be fined VND2-5 million ($86.16-215.40). Farmers found cultivating 500 to 3,000 plants could face jail terms of six months to three years, while those working on bigger scale could spend up to seven years in jail.