A man pried a crocodile's jaws from his head to survive an attack in northern Australia on Thursday, afterwards insisting he will soon return to the swimming spot, according to paramedics.

Local officials said the 44-year-old was swimming at Lake Placid, near the tourist hotspot of Cairns, when he was bitten by the reptile.

"He felt this sudden impact clasped on the top of his head, which he recognised to be a crocodile," said Queensland Ambulance Service paramedic Paul Sweeney.

"He put his hands into the jaws to prise them off his head and when he did so and let go the jaw snapped shut onto his left forefinger."

Sweeney said the man swam a considerable distance back to shore, fearful the creature would return and dragged himself onto the bank.

Emergency responders found the man sitting in a "remarkably calm" state.

While the man was left with puncture wounds to his head, face, shoulder and hand, he escaped without serious injuries.

"He's a very lucky man," Sweeney said.

Saltwater crocodiles are known to inhabit the area, but attacks are relatively rare.

Sweeney said the man was taken to a Cairns hospital and was expected to make a full recovery.

"He's quite a robust individual who insisted that he will be back swimming there soon. So, a braver man than I."