The Energy Ministry announced that from Saturday to Monday, petrol will cost no more than PLN 6.73 a litre, with diesel capped at PLN 7.88.
The next price announcement, covering Tuesday, is due on 5 October.
The caps are part of the government's "Lower Fuel Prices" package, now in its third phase.
The scheme aims to limit price rises at the pump and reduce costs for drivers.
It was made possible by a law signed on Thursday by President Karol Nawrocki.
The act imposes a 60 percent tax on excess profits made by fuel producers and companies licensed to trade fuel abroad between 1 March 2026 and 31 March 2027.
The law also allows temporary cuts to fuel excise duty and VAT.
The president has referred the legislation to the Constitutional Tribunal for review after its entry into force.
The government says the revenue will fund the support measures, which are due to run until the end of 2026 and could cost around PLN 5 billion (EUR 1.14 billion)
The first phase of the package began in late March, when oil prices were climbing because of the US-Israeli war with Iran.
It combined lower VAT and excise duty with a government-set price ceiling, and ran until the end of June.
A second phase, without the excise cut, ran from 17 to 31 August.
(ał)
Source: PAP