Saigon Jewelry Company gold bar dropped 1.05% to VND141.5 million (US$5,373.89) per tael. A tael equals 37.5 grams or 1.2 ounces.
Gold ring declined 1.39% to VND142 million per tael. Gold prices in Vietnam have fallen 7.4% so far this year.
Globally gold prices fell on Tuesday, pressured by a stronger dollar, while markets looked to the Federal Reserve's upcoming policy decision for clues on the interest rate outlook, Reuters reported.
Spot gold fell 0.7% to $4,044.81 per ounce after rising as much as 1% on Monday. U.S. gold futures for August delivery lost 0.8% to $4,045.40.
The dollar held near a one-month high, making greenback-priced bullion more expensive for holders of other currencies.
"We're oscillating in this narrow range between $3,950 and $4,200, and I think the market is just waiting for Fed signals," said Ilya Spivak, head of global macro at finance content network Tastylive.