Vietcombank sold the dollar at VND26,353, down 0.01% from Monday.
The State Bank of Vietnam lowered its reference rate by 0.008% to VND25,099.
On the black market the dollar rose 0.15% to VND27,380.
Globally the yen slid after hardline conservative Sanae Takaichi was elected as Japan's first female prime minister, as investors bet that the move could bring about a muddied rate outlook and greater fiscal largesse, Reuters reported.
The Japanese currency was last down 0.4% at 151.38 per dollar.
"While fiscal stimulus is expected, it is unlikely to be bold given the difficulties of policy management," said Hirofumi Suzuki, chief FX strategist at SMBC.
The U.S. dollar index was up 0.16% at 98.77, while the Australian dollar fell 0.21% to $0.6499.