Results from the 2014 Scottish Survey of Literacy and Numeracy found 47 per cent of S2 boys were doing well, very well or performing beyond the level they were being assessed for in writing, down from 58 per cent in 2012.
S2 girls whose writing was of this standard also fell, going from 70 per cent to 63 per cent over the period.
In the most-deprived communities, 41 per cent of S2 pupils were said to be “performing well, very well or beyond the level” with their writing, a drop from 54 per cent in 2012.
Performance in this age group in the least-deprived areas had also fallen, going from 74 per cent in 2012 to 64 per cent last year. Overall, 55 per cent of S2 pupils were said to be doing well or better at writing, down from 64 per cent in 2012.
In terms of reading, the survey found 80 per cent of S2 students were doing “well or very well”, compared to 84 per cent in 2012.
Performance was also poorer in primary schools, with 78 percent of P4 pupils and 88 per cent of P7 students reading at this level, compared to 83 per cent and 90 per cent respectively in 2012.
The literacy survey conducted in May 2014, saw 10,000 pupils and 2,250 schools take part.
In the wake of the results, education secretary Angela Constance has announced that Education Scotland inspections will focus on raising attainment in literacy, while ministers will work with partners to set up a new national improvement framework.
Teachers will also be given extra learning resources to raise the quality of literacy education.
During a visit to Calderwood Primary School in Rutherglen yesterday, she conceded the results are “not as good as they should be”.
She said: “Literacy and numeracy are vital skills for our young people. That’s why the survey was commissioned – to get a clear picture at various stages of school. And it is why we all must act on its findings.
“They demonstrate the need to re-double efforts to ensure that every child can succeed in school and so gain the skills they need for life.”
In response to the survey results, EIS, Scotland’s largest education union, welcomed the extra resources for teachers but called for further investment in schools and an end to austerity-driven budget cuts.
General secretary Larry Flanagan said: “Whilst it is important to analyse these findings and learn any lessons, the EIS is very clear that particular challenges remain for schools, teachers and pupils. For example, we have seen a drop in teacher numbers, a rise in class numbers, teacher workload at an unsustainable level and restrictive budget cuts reducing resources. Both local and national government need to realise that austerity has an impact on our schools and young people.”