The Finance Ministry said it may cut petrol retail prices and re-impose import tariffs in the second quarter if prices fall on the world market.
Otherwise prices could go up again, the ministry said, noting that even after the latest increase, local petrol prices are still lower than those in other countries in Asia.
Vietnam raised gasoline and diesel prices by up to 24 percent on Thursday.
Although the move was anticipated, many consumers said they were surprised by the extent of the hike, especially given that power prices are set to surge by 15.3 percent next month.
The Finance Ministry said it had kept prices stable for a long time in the context of rising world prices.
The government already cut import taxes and allowed fuel companies to use VND6.39 trillion from the price stabilization fund.
Now that the fund has run out of money, it had to raise prices, the ministry said.
Officials estimated that Thursday's price hike could push the national consumer price index up 0.65 percentage points. Inflation accelerated to a two-year high of 12.31 percent in February.