The UN report confirmed Australia as leading the world in the use of party drug ecstasy, third in methamphetamines and fourth in cocaine, Xinhua reported citing a Daily Telegraph report.
With codeine and morphine use, Australia ranks second only to the US with 3.1-3.6 percent of people aged between 15 and 65 considered regular users, mostly women.
More than 10 percent of the working-age population regularly use cannabis, with 1.9 million people aged 15-65 using it in the 12 months before figures were collected in 2010.
And except for ecstasy, the use of recreational drugs in Australia is increasing.
"Expert opinion points to an increase in the consumption of cannabis, cocaine, hallucinogens and solvents and inhalants but a decline in the use of ecstasy," the report said.
"There is a wide range of drug analogues and new psychoactive substances currently available in the Australian illicit drug market."
Australian Drug Law Reform Foundation president Alex Wodak said Australia's rise in illicit drug use was due to economic and social conditions.
"People on one hand have more money to spend and on the other there are more people who are at risk -- and those that are at risk are getting worse because of high unemployment, poor job prospects, lack of optimism," Wodak said.
He added that the concern for medical authorities was the increase in overdoses with more than three people dying each day from a drug overdose, the majority caused by opioid pill popping by women.
"What is more concerning is (that) overdoses are rising fast. They've been rising steadily for some years," Wodak said.
Australian National Council on Drugs Executive Director Gino Vumbaca said young people had easy access to drugs and police were not as vigilant as they were 10 years ago.
"Drug use was going down and we were dealing with a critical level of overdoses because a lot of investment and attention was going into the issue," he said.