Vietcombank sold the dollar at VND24,370, down 0.08% from Sunday.
The State Bank of Vietnam has reduced its reference rate by 0.08% to VND23,932.
The greenback went up 0.16% to VND24,740 on the black market.
It has increased against the dong by 2.70% since the beginning of the year.
Globally, the dollar started Monday on the front foot, with a reading on U.S. inflation and the Federal Reserve's last policy meeting for the year likely to set the tone for the week, while rising deflationary pressure in China leant on the yuan, Reuters reported.
The greenback pushed back above 145 yen and last bought 145.12 yen, reversing some of its steep fall against the Japanese currency late last week, as bets grew that the Bank of Japan's ultra-low interest rates policy may be nearing an end.
Sterling dipped 0.02% to $1.2545 and was huddled near Friday's two-week low of $1.2504.