Ho Chi Minh City doctors on Wednesday said 64 students fell ill after eating their lunches and afternoon snacks at a primary school.
The four worst cases were discharged from hospital after hours of treatment.
Other students recovered after resting at home.
Doctors said the students at Nguyen Thanh Tuyen Primary School in DIstrict 3 showed food poisoning symptoms, including nausea and headache, soon after having their snacks on Tuesday afternoon, which included steamed sticky rice and peanut.
They had rice, caramelized pork and eggs and vegetable soup for lunch.
The city's food safety agency said they had taken leftover samples to investigate into the case.