Two of the victims were killed when a radio tower collapsed in Dong Hoi, the Vietnam News reported. The storm also injured 31 people and left 4,800 structures damaged.
The typhoon hit the province of Quang Binh Monday, the News said.
Power lines connecting provinces and cities in the region were destroyed, leading to large-scale outages, officials said.
Local electricity agencies have worked to repair the lines, but several areas are still without power.
The storm has traveled to Laos, but is set to weaken in the next 12 hours.