The study, which examined the classroom performance of 400,000 15-year-old students in OECD nations between July and September this year, showed the Australians performed above the OECD average but have slipped in two of three main academic areas.
The results were dragged down by poor performances by indigenous students and those from a low socio-economic background, Fairfax newspapers reported today.
Students' reading, mathematic and scientific literacy were tested in the OECD's Program for International Student Assessment, released yesterday.
Only Finland, Hong Kong and Canada significantly outperformed Australia.
Australian students improved their ranking in scientific literacy, rising from fifth place in the last survey to fourth.
But their comparative reading ability declined, with Australian students in sixth place for reading literacy levels, down from second in 2000 and third in 2003.
Victoria was the worst performing mainland state. Its results were above the OECD average, but it ranked sixth in the country in each of the three test areas, beating only Tasmania and the Northern Territory.
“Something is happening in Victoria that's making Victoria perform at a lower level than NSW,” Geoff Masters, the chief executive of the Australian Council of Educational Research, told Fairfax.
“It's probably not starting age or the year that they transfer from primary to secondary school.
“The question we should be asking is: Is it something to do with the quality of teaching? Maybe not. Is it something to do with the curriculum? We don't know