Vietcombank sold the dollar at VND25,440, up 0.36% from Tuesday.
The State Bank of Vietnam raised its reference rate by 0.37% to VND24,231.
The dollar went up 0.27% to VND25,670 on the black market.
It has increased against the dong by 4.18% since the beginning of the year.
Globally, the dollar was broadly steady on Wednesday, keeping the yen rooted near 34-year lows after comments from Federal Reserve officials, including Chair Jerome Powell, suggested U.S. interest rates are likely to stay higher for longer, Reuters reported.
The euro was at $1.062, not far from the five-and-half-month low of $1.06013 it touched on Tuesday.
The yen was last at 154.65 per dollar, having touched the 34-year low of 154.79 in the previous session. The Japanese currency is down about 9% against the dollar this year.
Against a basket of currencies, the dollar was last at 106.33, just below the five month peak of 106.51 touched on Tuesday.
Top U.S. central bank officials including Powell backed away on Tuesday from providing any guidance on when interest rates may be cut, saying instead that monetary policy needs to be restrictive for longer, dashing investor hopes for significant easing this year.