Cambridge slipped to second, ahead of Harvard in third, University College London (UCL), fourth, and Oxford, fifth.
QS rank institutions based on an overall score calculated using ratings for six criteria; academic reputation, employer reputation, citations per faculty, faculty-to-student ratio, international proportion of faculty and international proportion of students. All scores are out of 100.
MIT was not ranked first in any of the six categories, but had four scores in the top 20. Cambridge and Oxford placed second for academic reputation and employer reputation respectively, with both beaten to first place by Harvard.
30 UK universities were ranked among the top 200 overall. Only the US, with 54, had more.
Despite representation high up the rankings, British universities were beaten by those of seven other countries in terms of the average score for academic reputation*.
Australian universities scored highest for this criterion, achieving an average of 92.
UK institutions fared better for employer reputation, where their average score of 76.8 was second only to Australia's 86.4.
British universities also scored highly for citations per faculty, coming in fifth place with an average score of 60.6 out of 100. Citations from within the same university were not included in the calculation of scores for this category.
The widest ranges of scores were seen in the criteria of international faculty and students. Hong Kong and Switzerland placed first and second for their universities' average international faculty rating, scoring almost six times as high as Japan.
UK institutions placed, on average, fourth for international faculty and third for international students. China and Japan occupied the two lowest places in both instances.
Below are the top 100 universities according to QS' 2012 rankings, along with their positions for the four previous years.
Click here for more information on the definitions, weightings and calculations used by QS.
*All country rankings exclude countries with fewer than five institutions in the top 200.