Dozens of workers at the company also fell sick in a similar case five months ago.
Health officials in Ho Chi Minh City are taking food samples from a Chinese-owned garment company to investigate a mass poisoning case that happened on Saturday.
The officials said 109 workers at Worldon Company in Cu Chi District had had to be rushed to hospital after having a lunch of ground fish braised with shrimp, stir-fried vegetables and cabbage soup.
Seven of the workers had to stay in hospital overnight, and doctors said they were suffering from food poisoning.
Dozens of workers at the company also fell sick after lunch in May.
Worldon Vietnam is owned by Shenzhou International, a Chinese clothing manufacturer based in Zhejiang Province in eastern China. The company employs more than 6,000 workers.
Food poisoning has been on the rise in Ho Chi Minh City over the past five years, mostly involving school and factory meals.
Last year, there were 171 cases of food poisoning that killed 23 people and sent nearly 5,000 others to hospital, according to the city’s Food Safety Agency.
Legal action is not often taken.
In March, HCMC fined South Korean fast food chain Lotteria Vietnam VND146 million ($6,500) for a mass poisoning case that sent 60 workers from a Danish company in hospital.
The city also fined Tam Tam Company, a local lunch provider, VND48 million ($2,200) after its food poisoned 44 primary school students in the city.