The Vietnamese supreme court on Tuesday sentenced a man from Dong Nai Province to death for burning his wife and child to death last September.
The trial was held to appeal the life-sentence handed to Nguyen Van Hay, 39, in May.
Two of Hay's young children were also badly burned in the fire and Dong Nai prosecutors said Hay should have received the highest penalty the law has to offer, news website VnExpress reported.
According to the indictment, Hay beat his wife unconscious while drunk in September last year. Prosecutors said he had accused her of having an affair without evidence.
The couples' three children had begged him to stop but Hay then poured gasoline on his wife and set her on fire, killing her and their oldest child, then 14 years old. The other two children, 12 and 10 at the time, were severely burned.
Hay then fled the house before it burned down, investigators said.
Judges at the Appeal Court said that "Hay knew clearly that his action would lead to the death of many people, but he still did it."
They agreed to impose the highest penalty since Hay's action violated many laws that call for the ultimate punishment.