Pat Pedraja looks like an average sport loving 13-year-old boy, but to a leukaemia patient who needs a bone marrow transplant, he is a hero.

Pat, from Florida, started the Driving for Donors initiative in 2007 after he watched other young patients die while waiting for a transplant.

Pat and his family drove all around the US in his ``Donormobile'', enlisting 11,000 new donors.

Even with leukaemia and chemotherapy, the savvy eighth grader with a big heart has struck a chord everywhere he has gone.

His goal while in Australia for the next two weeks is to register 2500 new donors during visits to Sydney and Melbourne.

``I want to keep inspiring people and get everyone to try and make a difference in their community,'' he said.

Pat won the CNN Heroes viewers' choice awards and his mother Claudine said he had become quite the celebrity.

On Monday, Pat met 19-year-old Petra Velkovski, from Prestons, who was diagnosed with acute lymphoblastic leukaemia when she was 16.

``I think it's amazing what he's doing he's an inspiration. We need more people like Patrick to raise awareness about donating,'' she said.

Ms Velkovski is now an ambassador for Cure Our Kids, helping others affected by

cancer.

Ms Velkovski, who has a Macedonian background, said it was important to enlist people with an ethnic background because Australia is very multicultural.

Clinical studies by the Australian Bone Marrow Donor Registry have shown that patients do better with younger donors and patients are more likely to find a match within their own ethnic group.

Sally Gordon, executive officer of the registry, said around 10,000 Australians are diagnosed each year with leukaemia or other fatal blood disorders.

Around 70per cent of people needing a bone marrow transplant will not find a match within their own family and must rely on the registry to find a donor.

``If everybody signed up to the registry, the whole world would have a match,'' Pat said.