Scottish Qualifications Authority statistics show A-C passes at Higher are down marginally by 0.2 per cent between 2017 and 2018.
National 5 qualifications have fallen 2.1 per cent while National 4 attainment has dropped 1.6 per cent.
The figures, updated from August to take account of issues such as appeals and late results, show there were 55,083 band A passes at Higher this year, 48,592 at B and 44,274 at C.
Scottish Labour said more education resources are needed to bolster attainment.
The party’s education spokesman Iain Gray said: “The SNP should be utterly ashamed of these figures.
“Education is supposed to be Nicola Surgeon’s top priority. Instead teachers are overworked and underpaid and schools have faced £400 million worth of cuts since 2010.
“Young people are being failed and opportunities are being cut off by the mess this government is making of education.”
Education secretary John Swinney said: “The reality is that a record percentage of school leavers have left with five or more passes at Higher or equivalent. This is part of a clear trend that has seen the proportion of pupils getting passes at Higher level or better rise more than 10 percentage points. All of this contributed to the record numbers getting apprenticeship, college, university places or a job.
“Curriculum for Excellence is helping young people to develop skills for learning, life and work, and when you look at attainment when pupils leave school, the gap between most and least deprived is generally narrowing, and overall attainment is up.
“We recognise pressures on teachers and have undertaken a range of actions to ensure a reduction in teacher workload, acting to clarify and simplify the curriculum framework and to remove unnecessary bureaucracy, while the education reforms being implemented by this government will also create new opportunities for teachers to develop their careers.”