Universities New Zealand is concerned by the big drop in the University Entrance pass rate among students from low-decile schools and Maori and Pasifika backgrounds.
Qualifications Authority figures show pass rates for those students tumbled by about a quarter following changes to the UE standard.
Universities New Zealand director Chris Whelan said a contributing factor may be be that many low-decile schools were small.
"It's harder for those smaller schools with more limited choices, particularly in Year 13, to offer the full range of curriculum.
"And we understand in some cases, availability of teachers, clashes of courses, meant that students just weren't able to get UE because of that."
Mr Whelan said universities would discuss the issue with the Qualifications Authority.