Brisbane residents are paying more for fuel than people in Sydney, Perth, Adelaide and Melbourne — and the RACQ says there is no good reason for it.

The motoring body's latest fuel price report shows unleaded petrol in Brisbane cost an average of 127.4 cents per litre (CPL) in May, which was four cents more than in Sydney and also more than in other large capitals.

It was the seventh time the Brisbane price topped the country in 12 months.

RACQ spokeswoman Renee Smith said even regional Queensland towns such as Miles, Bundaberg, Toowoomba and Whitsundays were cheaper than the capital.

"We have more than 300 service stations in Brisbane, yet our competition is weaker than some of the smaller regional parts of Queensland," Ms Smith said.

"It just goes to show competition isn't about the number of service stations in a town.

"There is no reason for Brisbane motorists to be paying more because freight costs don't apply in the south-east."

Brisbane was more expensive than Sydney, Perth, Adelaide and Melbourne, but motorists in Canberra, Darwin and Hobart paid even more for fuel.

The most expensive regional centres listed in the report were Innisfail and Blackwater, with an average price of 144.9 CPL and 144.4 CPL respectively in May.

ACCC and Federal Government should act

Queensland Minister for Main Roads Mark Bailey said the Australian Competition and Consumer Commission (ACCC) was best placed to regulate fuel retailers.

"The main retailers operate in a national market and I will be writing to the federal Treasurer to see what the Turnbull Government intends to do now to take national action," he said

"I am pleased the ACCC will also be taking a more detailed look into the Brisbane petrol market following our requests, and I look forward to the ACCC's report in coming months."

Queensland historically high

The ACCC said it was aware of the level of community concern about high petrol prices in Brisbane, which it said have been historically high in comparison with Australia's other large cities.

"The ACCC is examining these high retail prices, margins and profits in Brisbane and will release its findings in a separate short, dedicated report, which it intends to release in late-July," an ACCC statement said.

"Motorists can help drive petrol prices down by shopping around where possible and rewarding retailers that offer the most competitive prices.

"There are a number of price checking apps available that can help consumers find the best priced fuel in Brisbane, such as the MotorMouth app and website, and the GasBuddy app."