The government has changed poverty standards that will apply for the coming five years, from 2011 to 2015.
The new poverty lines, used to decide eligibility for social welfare benefits, have now been set at VND400,000 (US$20.5) per person per month for rural households and VND500,000 ($2505) per person per month for urban households, the government said in a report on its website.
Vietnam has experienced considerable improvements in living standards in recent years, with the national per capita income just hitting $1,200 a year.
The government's report said the number of families living below poverty lines fell from 22 percent in 2005 to 9.45 percent in 2010.
The previous poverty threshold was VND200,000 per month in rural areas and VND270,000 in urban areas.
Some cities and provinces have declared themselves free of poverty, based on these thresholds, including Da Nang, Ho Chi Minh City and Binh Duong, the report said.
It did not say how the new standards will affect the country's poverty rate.