The NSW Teachers Federation has supported State Education Minister Adrian Piccoli's call to scrap the My School website.
Mr Piccoli has argued the site is a waste of money and that publishing NAPLAN results puts students under unnecessary stress.
My School, introduced in 2010, was updated on Wednesday with the latest NAPLAN information, as well as data on school funding and student background.
Mr Piccoli said it was the publication of these results, not the tests themselves, that was damaging and the website was "of no real value".
"The bottom line is My School has negative impacts, it is used as a marketing tool for schools and the money spent on My School could be better used," he said.
NSW Teachers Federation regional organiser Nicole Calnan said the union had long been concerned about misuse of the website.
"NAPLAN is a snapshot in time, it's a test on one day. It can't replace the culmination of a whole year's work," she said.
"I would encourage parents to get that much more holistic view and the bigger picture of what their school is about by going to their school, being part of their school community and involving themselves in that to see all the opportunities their school provides."
She said shutting down the website wouldn't disadvantage parents.
"The information published on there is information schools produce already for their annual school report. Parents won't be missing out on that information if that site no longer exists."
In 2012, when in opposition, now Federal Education Minister Christopher Pyne said a Coalition government would axe the site's publication of individual school results.
A spokesman said the site would be retained but "as promised, we will look to ensure it is a useful tool for parents and educators".
The Illawarra has a year 12 retention rate 7percentage points lower than the state average, according to the latest data from the Department of Education.
But an Illawarra principal said these figures didn’t adequately reflect the improvements in retention rates in the region over the past several years.
In 2012, retention rates for the Illawarra and South East, which extends to the Victorian border, for year 10 to 12 sat at 63.3per cent, below the NSW average of 70.7per cent.
The region lagged behind northern Sydney, with retention rates of 90per cent, as well as south-western Sydney and western Sydney, with retention rates of almost 75per cent.
However, Mark King, a member of the state assembly of the NSW Secondary Principals’ Council, said he understood retention rates at schools in the Wollongong and Wollongong north area were now higher.
Retention rates in the region increased almost 5percentage points between 2008 and 2012, and at Corrimal High School, where Mr King is principal, year 10 to 12 retention rates jumped from 52per cent in 2012 to 68.3per cent last year.
He attributed the improvement to the work schools had done in diversifying the curriculum for both students who were after an ATAR and those seeking employment once they finished school, working closely with TAFE and mentoring students on their options post-school.
‘‘Putting all of these things into place has certainly met these kids’ needs,’’ Mr King said.
Opposition spokesman for education and training Ryan Park said while there had been improvement, more needed to be done to encourage students to complete year 12 in order to enhance career prospects.