The SNP has been accused of “destroying Scotland’s once world-leading education system”.
All three opposition party leaders rounded on Humza Yousaf during FMQs on Thursday to scold him on the recent global education study.
The Programme for International Student Assessment (PISA) study found Scotland’s ranking had slipped.
The country came second last among the UK nations for science and maths and was below England on all measures.
Scotland’s reading level remained above the OECD average.
Scottish Labour leader Anas Sarwar said pupils and teachers are doing a “great job” but are “being let down by this pathetic SNP government”.
He said: “This SNP government’s record and education is a litany of broken promises. Closing the attainment gap, promise broken. Guaranteeing class sizes of 18 or under, promise broken.
“Free school meals for all primary school pupils, promise broken. A digital device for every pupil, promise broken.
“Year after year the SNP make promises to Scotland’s children but year after year they fail to deliver and after 16 years there is no one else to blame.
“So will the First Minister apologise to the people of Scotland for destroying our once world-leading education system?”
Yousaf admitted Scotland was hit with a “poor” set of results from the PISA score but would not say sorry.
He said: “I will not apologize for additional support needs results that show the biggest single-year fall in the attainment gap in primary schools in both numeracy and literacy.
“No I won’t apologise for the fact that we have more children, more young people, from areas of deprivation going to university.
“Do I want to apologise for a record number of young people aged 19 who have now secured a university place this year?
“No I won’t apologise for the 94.3% of 16 to 19-year-olds that were participating in employment, education or training over the past year.
“So yes there are challenges. Yes the PISA results are serious and we will reflect on that, consider those results and come forward next week with more detail on the action we will take.”
Scottish Tory leader Douglas Ross said a “generation of young people had been failed by the SNP”.
He described Scottish Government’s record on schools as a “national disgrace”.
Scottish Liberal Democrat leader Alex-Cole Hamilton added that the SNP are “squandering the once proud global advantage Scotland held education”.
He said the nation’s PISA results were its worst on record.
The education secretary will update parliament next week on the “practical actions” the Scottish Government will take on schools.
Follow STV News on WhatsApp
Scan the QR code on your mobile device for all the latest news from around the country