A woman in the central province of Nghe An died on Thursday, three days after her husband set her on fire and burned their son alive.
Family of Nguyen Thi Oanh Dam, 22, said she died at a local hospital during treatment.
Dam suffered severe burns almost all over her bodies after her husband poured gasoline and set her on fire Monday night, after she complained about him coming home drunk.
She was breastfeeding their 9-month-old baby. The child caught on fire and he died soon after that.
The family had rushed Dam to the National Burns Institute in Hanoi but doctors said she would not survive.
They then brought them back to their hometown.
Police in Nghe An have arrested the 25-year-old husband Tran Van Giang.
He will be investigated for murder.