Vietcombank sold the dollar at VND24,660 Friday, up 0.20% from Thursday.
The State Bank of Vietnam reduced its reference rate by 0.02% to VND23,971.
The greenback fell 0.12% to VND25,050 on the black market.
The dollar has increased against the dong by 0.98% since the beginning of the year.
Globally the dollar was steady on Friday, on track for its fifth straight weekly gain, as investors take stock of economic data and firm expectations of the Federal Reserve cutting rates in June, while the yen traded at the psychologically key 150 per dollar level, Reuters reported.
The dollar index, which measures the U.S. currency against six major rivals, was up 0.09% at 104.35 on Friday, having eased 0.4% on Thursday. The index is on course to eke out a 0.2% gain for the week, its fifth in a row.