Man survives 20m Cairns waterfall drop

A man is lucky to be alive after falling about 20 metres from a steep waterfall near Cairns.

The 23-year-old fell from Crystal Cascades waterfall and crashed into rocks before tumbling into the water on Wednesday afternoon.

His friends and bystanders performed basic first aid until rescue teams arrived, Queensland Ambulance Services senior operations supervisor Neil Noble said on Wednesday.

"This gentleman is extremely lucky to be alive ... we have had fatalities at the same waterfall," Mr Noble said.

"He was able to remain conscious the whole time, but were it not for the basic first aid provided by the bystanders it could have turned out to be a very, very serious situation."

The man was taken to Cairns Hospital in a serious but stable condition with a suspected fractured leg, possible fractured pelvis and spinal injuries.

"The message is very clear - do not go in unrestricted areas and do not jump off waterfalls," Mr Noble said.

"If you're going to partake in these exercises we really advise that you go with a group of people and certainly professionals that run the tours."