A report commissioned by the Welsh Government has found that the Welsh Baccalaureate may be ‘detrimental’ to university performance.
It found students with the Welsh Baccalaureate qualification are less likely to get a ‘good' degree than those who studied A-Levels.
The Welsh Baccalaureate is taken by more than 70,000 students.
The research, conducted by Cardiff University, found those without the Welsh Qualification are more likely to achieve a 2:1 or First at university.
But the report by the Wales Institute of Social & Economic Research did find that the Welsh Baccalaureate does improve the chances of getting into university.
The researchers also identified three ways in which the qualification could be improved. These included better promotion of the exams, increasing the difficulty and tailoring the qualification to the particular needs of students.
The Welsh Baccalaureate was first introduced in September 2003 as a pilot scheme involving 18 schools and colleges.