Hand, foot and mouth disease (HFMD) has claimed 27 children's lives out of around 50,000 infections so far this year, according to the latest statistics from the Health Ministry.
The ministry said the number of HFMD infections is 10 times higher than the same period last year, and all the fatalities were caused by the Enterovirus 71 (EV-71).
The figures have far exceeded any previous predictions.
Health experts have said the disease would continue to spread over the next few months.
Cities and provinces with the most HFMD cases include Hai Phong, Lao Cai, Vinh Phuc, Da Nang, Yen Bai and Quang Tri.
The ministry has repeatedly advised adults and children to wash their hands frequently and thoroughly, especially after they use the toilet and before they eat.
Adults should also keep their children's toys clean and restrict them from putting any toys or other tools into their mouth, the ministry said.
Last year, the disease claimed 169 lives out of 110,000 infections.