Technology is being used to help save lives with virtual reality lessons cutting down the time it takes to train Victorians in CPR.

St John Ambulance, in partnership with Start VR, on Tuesday launched the Australia-first virtual reality service which reduces training time by 75 per cent.

Training session that previously lasted half a day, can be completed within an hour.

Wearing virtual reality head sets, first aid students are presented with a real-life simulation of a medical emergency and are guided through the various stages of CPR training.

St John Ambulance Victoria chief executive officer Gordon Botwright said his organisation recognised that time is precious for people who want to be trained in CPR.

"With thousands of people dying from cardiac arrest each year, it's crucial that we make the process of undertaking first aid training accessible," he said.

Research has shown that students retain 70 per cent more information after training with virtual reality, compared to traditional lecture-style teachings.