Forty people were missing and 21 others were injured after rains caused landslides and flooding, mostly in northern and central Vietnam.
'Our entire village had sleepless nights...it's impossible to fight against this water, it's the strongest in years,' Ngo Thi Su, a resident in northwestern Hoa Binh province, was quoted as saying by state-run Vietnam Television (VTV).
Vietnam often suffers from destructive storms and floods due to its long coastline. More than 200 people were killed in storms last year.
A typhoon tore a destructive path across central Vietnam just last month, flooding and damaging homes and knocking out power lines.
The latest floods hit Vietnam on Monday.
Vietnam's Central Steering Committee for Natural Disaster Prevention and Control said authorities were discharging water from dams to control water levels.
In a report, it said more than 17,000 households have been evacuated and more than 200 homes have collapsed, while nearly 18,000 other houses were submerged or damaged.
It said more than 8,000 hectares of land growing rice was damaged and around 40,000 animals were killed or washed away.
Hoa Binh province in the northwest declared a state of emergency and opened eight gates to discharge water at Hoa Binh dam, Vietnam's largest hydroelectric dam, the first time it has done so in years, VTV reported.
Prime Minister Nguyen Xuan Phuc visited northern Ninh Binh province where water levels in the Hoang Long river are their highest since 1985.
Rising sea levels are also threatening Vietnam's more than 3,260 km (2,000 mile) coastline, resulting in increased flooding of low lying coastal regions, erosion and salt water intrusion.