The 876 candidates in Sunday's election for 500 seats include 30 "self-nominated" people.
This is double the number who stood in the 2002 election and comes after the country's Communist leadership appealed for more independent candidates to stand.
"We hope that among these there will be more people elected to parliament, because last time only two independent candidates were elected," Nguyen Si Dung, an electoral expert in the National Assembly office, said.
In total 150 of the candidates are not members of the Communist party, the country's only legal political party.
Its members have begun aggressively questioning government ministers, and they carefully review drafts of laws submitted by government agencies.
The assembly has made a priority of cracking down on corruption, which is widespread in Vietnam.
The country's gradual political liberalisation comes as Vietnam moves to assume a greater role in East Asian politics, joining the World Trade Organisation in January and moving to end decades of self-imposed political isolation.