Independent school pupils make up a disproportionately high number of the sixth years entered for the new Scottish Baccalaureates in languages and science.
Of only 23 pupils entered for the languages bacc, 14 are from state schools and nine from the independent sector. In science, where there is a significantly higher uptake, 122 entrants are from state schools and 31 from independents.
Last month, The TESS also revealed that a third of pupils who originally entered for the new qualification had withdrawn.
Carole Ford, past president of School Leaders Scotland and head of Kilmarnock Academy, said: "The low uptake of the new baccalaureate qualification is disappointing, but not surprising. Of more concern is the fact that this qualification is currently dominated by pupils from the independent sector."
She added: "Pupils in private education account for just less than 5 per cent of the total pupil population, but nearly 40 per cent of the language baccalaureate entrants and more than 20 per cent of the science.
"Staffing levels in the state sector are the major barrier to uptake and, until this is addressed, universities and colleges must be very wary of according it any additional credit in the SCQF (Scottish Credit and Qualifications Framework)."
However, Judith Sischy, director of the Scottish Council of Independent Schools, said she believed the Scottish bacc would be highly valued by universities.
The higher uptake of the bacc by independent schools could be explained by the fact that a larger proportion of their pupils do science or languages at Advanced Higher and Higher levels, Mrs Sischy suggested.