Australian women will now be better protected against cervical cancer under the new national screening program, experts say.

Women are being urged to take part in an updated national screening program that promises to protect millions from cervical cancer.

Women now only have to undergo the new test every five years - no longer needing to have a pap smear every two years.

Launched on December 1, the new test will for the first time screen for the Human Papillomavirus Virus (HPV).

Cervical cancer is caused by sexually acquired infection with certain types of HPV. Two HPV types - 16 and 18 - cause 70 per cent of cervical cancers and precancerous cervical lesions.

Cancer Council NSW's Karen Canfell, who was part of the research team that drove the changes, says the test will increase detection of precancerous lesions.

"Because the new cervical screening test actually tests directly for the virus that causes cervical cancer, it's a molecular test which is much more sensitive," Professor Canfell told AAP.

"That's the reason it will pick up any changes to cells at a very fundamental level and therefore offer better protection against cervical cancer."

Women will get their first invitation to screen on their 25th birthday.

Professor Canfell says after the introduction of the new screening program, many countries are now looking to Australia to follow its lead.

"This is really up there in terms of being really one of the important innovations in cancer prevention," he said.

"Just as we've had HPV vaccinations now for 11 years I really think this is the next major step in improving cervical cancer prevention for women in Australia."