With 446 "yes" votes out of 490 valid ballots cast by the National Assembly (NA) deputies, Phuc was approved to be the new prime minister at the 11th session of the 13th NA, Xinhua news agency reported.
Phuc, 61, was chosen to replace Nguyen Tan Dung, who was relieved from the duty of Vietnamese prime minister on Wednesday.
"I swear to be absolutely loyal to the nation, the people and the Constitution of the Socialist Republic of Vietnam," Phuc said.
He also pledged to make every effort to fulfil the duty assigned by the Vietnamese party, the state and the people. (IANS)