Women academics are being discriminated against in terms of money and promotion, lecturers claim.
Women are concentrated in lower academic ranks
They are held back by a glass ceiling which keeps most in lower-paid and lower-status jobs, according to the Association of University Teachers (AUT).
The group says that the number of women in academic life has soared by 43% since the mid-1990s.
But women are more likely to be on short contracts and in lower-paid jobs.
A study by the AUT found that the number of female academics in higher education in the UK rose by 43% to 56,500 between 1995-96 and 2002-03.
At the same time the number of male academics grew by 4% to 89,000. In all, 39% of academics are now women.
But the report, called the Unequal Academy, says that women are much more likely to have a fixed term contract rather than a staff job.
In 2002-3, 48% of women academics were employed on a fixed term contract, compared with 38% of men.
In the modern universities, in 2002-03 53% of academics on the lecturer grade were women, but only 30% of department heads.
In the older universities, 39% of the most junior lecturers were women, compared with 13% of professors.
Sally Hunt, AUT's general secretary said: "This report provides yet more evidence of the discrimination faced by women working in our universities.
"They are paid less, are more likely to be employed on a casual basis and continue to occupy the more junior grades.
"It is time for our universities to take some real action to solve this scandal."
The AUT says female academics working on a full-time basis earned 85% of the salary of their male colleagues in 2002-3.
They were also less likely to be described as being active in research.