Vietcombank sold the dollar at VND25,463, down 0.08% from Thursday and lowest since Nov. 12.
The State Bank of Vietnam kepts its reference rate unchanged at VND24,251.
The greenback dropped 0.19% at unofficial exchange points to VND25,790.
It has risen against the dong by 4.14% since the beginning of the year.
Globally the yen jumped as much as 1.2% against the U.S. dollar to a six-week high on Friday, after faster-than-expected inflation in Tokyo supported bets for a Bank of Japan interest rate hike next month, Reuters reported.
The dollar sagged against most major peers in trading thinned by the U.S. Thanksgiving holiday, with sterling, New Zealand's kiwi and the Chinese yuan all rising to the strongest levels in more than a week.