Australia has been ranked 39 out of 41 high- and middle-income countries in achieving quality education, in the latest international report to find that the country is falling behind in basic measures of teaching and learning.
Only Romania and Turkey were ranked below Australia in education in the latest United Nations Children's Fund (UNICEF) report card.
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The report looks at the performance of 15-year-olds in reading, maths and science, as well as the quality and level of access to early schooling, in 41 European Union and OECD countries.
The report found that only 71.7 per cent of Australian 15-year-olds are achieving baseline standards in the three key areas of education, based on the latest PISA assessment, and only 80.3 per cent of children are attending "organised preschool learning" for at least a year, according to 2014 figures.
By comparison, 81.4 per cent of Finnish 15-year-olds are achieving the minimum standard in reading, maths and science and 99.8 per cent of children attend organised early schooling in Finland, which was the top-ranked country for quality education.
UNICEF Australia's director of policy and advocacy Amy Lamoin said the latest report "provides a fuller picture" of the country's declining performance.
"Education is such a strong predictor of life outcomes and we're setting a fairly concerning trajectory," Ms Lamoin said.
"There's certainly a decline in real terms in the education space in Australia, partly because we have yet to see education reform that goes beyond funding-model debates.
"At the same time, other countries are making great gains and testing different things in their education systems."
Ms Lamoin pointed to Scandinavian countries as successful examples of this, with Finland, Denmark and Norway all ranked among the top 10 for education.
"Inclusive education is really a big part of policy in Scandinavian countries, which see students as citizens who are making strong decisions in their education," Ms Lamoin said.
"There's a lot of experimentation and discovery in their learning, and shorter school days with more focus on extra-curricular activities.
"Some people would question that approach but we follow a very set curriculum and the outcomes show that our 15-year-olds are falling behind."
A spokesman for the NSW Department of Education said it "has a relentless focus on improving student achievement in literacy and numeracy across all key learning areas".
"The department's literacy and numeracy advisers provide professional learning resources and online support for teachers and leaders across the state to support teaching, learning and assessment of students," he said.
Ms Lamoin said quality early education was also an important part of children's development that is often overlooked.
"In terms of a child's life, access and quality of education in early years sets the track for how they engage with school over the next 10 to 15 years," she said.
Each of the highest ranking countries has organised preschool participation rates of nearly 100 per cent. About 99.9 per cent of children attend at least one year of preschool learning in Malta, which was ranked second for quality education.
Only four countries had preschool participation rates below 90 per cent and only Turkey, where 72.7 per cent of children attend early education, scored below Australia.
The report notes that: "Both the quantity and the quality of [organised preschool] services for children from the age of 3 vary substantially across countries."
The NSW Education Department spokesman said that more than 95 per cent of children in the state "attend an early childhood education program", but did not specify what proportion of programs provide "organised preschool learning".
The overall report card assesses the status of children in high-income countries against the UN's global sustainable development goals across nine areas.
Australia has an overall rank of 21 out of the 41 countries but performed below average in education and eliminating hunger, in which it was ranked at 28.
The report found that 16 per cent of Australian children below the age of 15 lacked secure access to sufficient, safe and nutritious food.
At the other end of the spectrum, Australia is ranked third in making its cities inclusive and sustainable, coming behind Ireland and Norway.
It is ranked at 12 in eliminating poverty and has average rankings in the remaining areas of good health and wellbeing, decent work and economic growth, reduced inequalities, responsible consumption and production, and peace, justice and strong institutions.
The countries in the order of their education ranking are: Finland, Malta, South Korea, Mexico, Denmark, Belgium, Germany, Canada, Norway, Japan, Switzerland, Spain, Ireland, France, New Zealand, Sweden, the Netherlands, Latvia, Italy, the United Kingdom, Estonia, the Czech Republic, Slovenia, Portugal, Luxembourg, Austria, Iceland, Israel, Lithuania, Hungary, Poland, the United States, Greece, Cyprus, Slovakia, Croatia, Chile, Bulgaria, Australia, Romania, Turkey.