Police in the northern province of Hai Phong have to arrested a 29-year-old man for growing cannabis.
Officers raided the home of Do Xuan Hieu on Wednesday, and seized 859 marijuana plants.
Hieu said that after graduating from university, he had been unable to find a job and had become addicted to drugs. Hieu intercropped the drugs with other plants in an attempt to deceive officers.
Police are investigating further.
Marijuana is illegal in Vietnam, and the cultivation of it is punishable by up to seven years in jail.