There are warnings of a lack of "ethnic mixing" in the UK's universities, in a study from the Institute for Policy Research at the University of Bath.
Ethnic minority students are more likely to be concentrated in new universities in London and big cities.
But white students are more likely to attend predominantly white institutions, says the study.
The report warns of "segregation" as a result of students' choices of university.
There are also ethnic divisions within subjects, with only 25 black Caribbean students entering medicine or dentistry courses in 2014-15.
"If we are to create a more tolerant UK society, where people are aware and respectful of cultural and ethnic difference, it is vital that greater mixing happens," said leader of the research project, Dr Michael Donnelly.
The study, Diverse Places of Learning?, shows that black and Asian students are not spread evenly within the university system, but tend to be concentrated in big, multicultural cities.
Almost two-thirds of students in the UK from Bangladeshi families go to a relatively small number of "super-diverse" London universities.
There are some universities where almost three-quarters of UK students are from ethnic minorities - and there are others where more than 95% of students are white.
There are about 20 universities where a majority of undergraduate students are from ethnic minorities - with these figures not including overseas students.
Researchers found some students from multicultural parts of London were worried they could face racism if they chose universities in less diverse parts of the country.
Young people from ethnic minorities told researchers they were concerned about "feeling uncomfortable or thought they might be stared at" if they went to places with few other minorities, said Dr Donnelly.
White students, particularly those who have grown up in areas with a low proportion of ethnic minorities, were more likely to go to universities with a high proportion of white students.
"Only 12.3% of white British students attend the most diverse universities," said the study.
The researchers said it raised questions about integration and social mobility.
'Hierarchy of universities'
Report lead author Dr Sol Gamsu said that universities which are more ethnically diverse tended to be "less wealthy universities which provide higher education for large numbers of first-generation university students".
Dr Gamsu said that the "hierarchy of universities" meant that resources were more likely to be focused on "institutions dominated by the white middle class".
He said that in terms of factors underlying the segregation, there also seemed to be a pattern of middle class, white students avoiding some universities.
Subjects were "even more segregated than universities" said researchers and some have "huge problems with ethnic diversity".
For medicine and dentistry courses, the study found only 0.3% of the intake were from black Caribbean families - representing 25 students.
This was the lowest proportion of any ethnic minority group - compared with almost 3% who were black African, 11% Indian and 5% Pakistani and 2% Chinese.
For veterinary sciences, almost 95% of students were white, meaning that "fewer than 50 students starting out on new veterinary courses for 2014-15 came from non-white backgrounds".
Dr Matt Dickson, from the University of Bath's department of social and policy sciences, said that the study showed that more needs to be done to ensure that "students from different classes and ethnic backgrounds learn together in the same institutions".
He warned it should not be a system that "funnels" ethnic minority and poorer students "into certain institutions and the white middle class into others".