As of Friday, at least 25 people had been killed and another eight listed as missing in new flooding that had begun on Sunday in the central region, the Central Committee for Storm and Flood Control reported.
Although rains have stopped in most of provinces and water levels in local rivers have started decreasing, many localities are still heavily flooded, according to the committee.
Landslides triggered by floods made the situation worse, blocking many roads, it said.
Since the end of September, Vietnam's central coast has been hit by four rounds of flooding, leaving 200 people dead, damaging thousands of houses as also thousands of hectares of crops.
Meanwhile, a downpour lasting three hours on Friday in Ho Chi Minh City submerged many streets in the southern metro, causing traffic chaos.
Le Thi Xuan Lan of the Southern Meteorology Station said the southern region will be hit by torrential rains over the next days, most likely in the evenings.