Effective Saturday, Dec 1, all cigarettes or tobacco packs in Australia will be sold in identical, olive-brown plain packaging.

And this early, the new packaging on tobacco products, according to Federal Health Minister Tanya Plibersek, has already instilled some "psychological effects" on smokers.

"I have had a few letters . . . with smokers saying to me, 'Oh the cigarettes don't taste the same as they used to'," Ms Plibersek told reporters in Sydney.

"It (has become) less attractive to smoke," she said, although it was only the packaging that was changed. The ingredients of the pack's contents, the tobacco or cigarette itself, did not change.

Todd Harper, Cancer Council Victoria chief executive, citing results from a study conducted by the council, said smokers seem averse to the taste of plain-packaged cigarettes, claiming it tastes worse than branded cigarettes.

"I think this gives some clues as to why the tobacco industry has been so desperate and so committed to spending money, doing whatever it takes, to block plain packaging," he said.

"They know the impact it will have on people's perception of smoking and also the taste of smoking."

Under the new law, tobacco or cigarette makers are required to package their products using drab, olive-brown packets with expanded graphic health warnings that must feature very graphic images such as gangrenous feet and mouth cancer.

"That's the aim of this exercise," Ms Plibersek said.

"The challenge for us as a government is to make it (smoking) as unappealing as possible. If we can prevent young people from taking it up, that's a lifetime gift to them."

Stafford Sanders, Protecting Children from Tobacco Coalition coordinator, said the law is very important to educate the young people, especially those who start smoking before even turning 18.