The proposal, which has already been introduced in European countries such as France and the United Kingdom, has been welcomed by health experts.
But it hasn't got the backing of the major parties.
Greens Leader Richard Di Natale has stepped up his fight against sugar, proposing a 20 per cent tax on sugary soft drinks and fruit juice.
He says that will save the economy $2 billion over the next four years.
"That's two billion dollars we can save on our health system, that we can invest in prevention, that we can invest in our dental system. But there's no question that when it comes to sugary drinks, that is a major contributer to the obesity crisis that we have here in Australia."
Richard Di Natale made the proposal during the fifth Obesity Australia Summit at the University of Sydney.
Health groups attending, including Jane Martin from the Obesity Policy Coalition, backed the Greens suggestion.
"This would be a really important lever and nudge to encourage people to drink less of these sugary drinks which are so harmful to health and a huge contributor to overweight and obesity."
Professor Bruce Neal, from the George Institute for Global Health, says a tax on sugary drinks is the first of many measures that need to be implemented.
"It's not a silver bullet, it's part of the solution. We also need to be talking about advertising controls, particularly protecting our children from really predatory advertising by some of the big companies. And this is just a first step."
But Australian Beverages Council Chief Executive Geoff Parker believes the tax will be ineffective.
"Less than two per cent of the average Australian's dietary kilojoules actually come from soft drinks. So trying to put a tax on two per cent, while ignoring the other 98 per cent, ignoring issues like physical activity, sedentary behaviour, really lacks commonsense and it's just too much of a simplistic solution to what is a far more complex problem."
Several countries across Europe have already introduced a soft drink tax, including France, the United Kingdom, Finland and Hungary.
The global campaign is led by British celebrity chef Jamie Oliver.
Child Health Expert Professor Louise Baur welcomes the push.
"There's no nutritious value to having soft drink. It might taste nice, but it's not going to contribute to health in a child or young person. So if children and young people can consume less soft drink, we know that dental caries rates are likely to decrease. We know it will be one of the strategies to help tackle obesity."
If the proposed tax ever did became a reality, it would add about 40 cents to the average bottle of soft drink.
But Richard Di Natale says that could lead to a fall in consumption of 12 per cent, and save hundreds of lives a year.
"We know that a small increase in the price of these drinks will decrease consumption and reduce the incidence of diabetes, heart disease and strokes."
Both major parties have already said they have no plans to pursue a sugar tax.
But the Greens say they're confident one party will eventually come on board.
