A declaration by the Queensland Industrial Relations Commission means stores in the Brisbane CBD - in the 4000 postcode - will be allowed to open non-stop from April 3 to 17.

The application, brought by the National Retail Association, was made possible as a result of trading hours legislation that came into effect in September, allowing unrestricted trading for declared special events.

Unlimited trading was already in place in Queensland for independent stores, bakeries, butchers, chemists, service stations and restaurants.

But the commission's declaration will allow supermarkets, department stores and shopping centres to also stay open 24 hours a day in the Brisbane centre.

Bosses will not be able to force their employees to work extended hours during the Games.

Lord Mayor Graham Quirk said the Commonwealth Games would attract hundreds of thousands of visitors from across Australia and internationally.

"Brisbane is excited to be hosting the Commonwealth Games cycling and shooting events, and we expect visitor numbers to grow as a result of the two-week sporting event," Cr Quirk said.

Cr Quirk said major events added $100 million annually to the city's economy and boosted jobs that supported hotels, restaurants, cafes and retailers.

"We want the world to know we are open for business, and 24-hour CBD trading during the Commonwealth Games will allow visitors to experience the New World City lifestyle we know and love," he said.

National Retail Association chief executive Dominique Lamb said international visitors often expected longer trading hours, and the changes would allow the economy to benefit from the influx of tourists.

"Effectively it will mean everyone in that 4000 precinct, within the Brisbane CBD, will be allowed to trade, no matter how big or how small you are," she said.

The declaration also applies to shops in the Gold Coast City Council area.

Industrial Relations Minister Grace Grace said allowing 24-hour trading in the Brisbane CBD and Gold Coast during the Commonwealth Games was great news for the landmark event.

"It means visitors and locals will have more options to get out and enjoy all that the Games has to offer, and enable us to showcase our two biggest cities to the world," she said.

"It's consistent with the aims of our trading hours reforms, which aim to create more jobs, boost the economy and give consumers more choice."

It does not affect the hours liquor can be sold at bottle shops or lock-out laws in Brisbane.

The Commonwealth Games will host more than 6600 athletes and team officials from 70 nations and territories, supported by almost 15,000 volunteers, and broadcast to a global audience of 1.5 billion.

The Games were anticipated to attract about 672,000 visitors, generating more than $320 million.