More than 122,000 people had been moved to safe ground in several provinces, including Quang Nam and Danang city, by late Monday before the typhoon arrived, the official Tuoi Tre (Youth) newspaper reported.
Nari later hit the Vietnamese coast with wind speeds of up to 102 kmh (63 mph).
Soldiers were sent to help people reinforce their homes and guide ships to shelter in Danang, a famous tourist destination, state-run Voice of Vietnam radio said.
More than 2,000 passengers were stranded when national carrier Vietnam Airlines canceled 14 flights on Monday and planned to delay another eight on Tuesday, the airline said in a statement.
Vietnam's central region is widely exposed to the sea and is often hit during the storm season between July and October. Typhoon Nari did not affect the Central Highlands, Vietnam's coffee belt, which lies further to the south.
Nari was moving west at about 15 kmh (10 mph) and was expected to weaken into a tropical depression later on Tuesday, the national weather station said.
(Reporting by Ho Binh Minh; Editing by Paul Tait)
