South Koreans topped the list of visitors at 119,636, down 31% from August, according to the General Statistics Office.
So far this year Vietnam has received 1.87 million foreign visitors, only 37 percent of its full-year target.
The target of five million arrivals is only equivalent to 30% of pre-pandemic levels, and tourism insiders remain worried strict visa policies will stymie recovery.
Vietnam is providing visa-free stay to citizens from 24 countries, while the Thai government has increased the period of visa-free stay for tourists from over 50 countries from 30 days to 45 with effect from October 1 while Indonesia resumed its visa-on-arrival program.
The Russia-Ukraine tension and China's "zero Covid" policy has had a major impact on Vietnam's tourism recovery as China and Russia used to be Vietnam's biggest markets before the pandemic, VNAT said.
The government is considering issuing e-visas to nationals of more countries.
It now issues 30-day single-entry visas online to people from 80 countries and territories, including Australia, India, the U.K., and the U.S.