Australian emergency workers on Tuesday said they rescued a man who was stuck in a Brisbane storm drain for 36 hours after apparently trying to retrieve a dropped mobile phone.

The man, in his 30s, reportedly entered the tropical city's grimy underworld at the weekend.

After refusing a passerby's initial offer of help on Sunday, he was forced to drink drain water as he looked for a way out.

Emergency services were eventually alerted to the scene when a resident heard heavy breathing from the drain around 11 am on Monday.

Queensland Fire and Emergency Services told AFP that firefighters arrived and were able to lift the lid of the drain and rescue the man.

He was said to be suffering from abrasions and cold exposure and was transported to Mater Hospital.

Emergency services said he was in a stable condition.

Brisbane has faced days of wet weather and rain poured down the drain while the man was stuck inside.

Passerby James Lingwood told local media he had already spotted the trapped man on Sunday, hearing yells coming from the drain while out for a run.

"I said 'are you OK can I help you', he said 'no bro I'm all good' but he's knee deep in water and I'm thinking what do I do," Lingwood told the Courier Mail.

"But he seemed to be okay and he said he could get out where he got in so I just left him alone.

"I wanted to help him when I first saw him, but he didn't want my help. I don't think he thought he was in any great danger at the time", Lingwood added.

"You don't often see somebody down the drain, especially when there's rats and snakes and mosquitoes and all sorts of things going on," he said.

It was not immediately clear if the man retrieved his phone.