The group of eight college students met for a drink in Thu Duc on Thursday night, with one later found dead at his residence.
Seven others later showed signs of abdominal pain, dizziness and vomiting, and despite taking medication, grew sicker. Those experiencing convulsions, lethargy, and coma were transferred to hospital.
One of the seven hospitalized students was confirmed dead soon after arrival.
Doctor Tran Thanh Du of Gia Dinh Hospital where four students are being treated said they had signs of methanol poisoning and are in critical condition.
The two others are now being treated at Thu Duc Regional General Hospital.
Police have launched an investigation into the case.
It is not uncommon for vendors or producers to mix industrial alcohol with other liquor to save costs, causing a slew of deaths and related complications.
Most alcoholic beverages contain low levels of methanol, causing no harm. High levels of methanol, however, may lead to neurotoxicity and organ failure.