Ireland's top two universities, Trinity College and University City Dublin (UCD), have fallen out of the world's top 100 universities, according to an international comparative table published on Thursday.
The Times Higher Education Rankings lowered Trinity College by 40 points to position 117 in the world while UCD fell more than 60 points to 159.
The ranking table also downgraded many other Irish universities such as University College Cork (UCC) and NUI Galway which were lowered to below the world's top 300 universities.
Dublin City University (DCU) and Dublin Institute of Technology were also lowered to below the top 400 universities.
This is the second such ranking system published recently that shows a clear decline in Ireland's university education system.
Irish universities responded by saying that this was due to recent government spending cuts in education.
The publishers of the ranking table also said the reason for this was that the student to staff ratio had increased during a time of education spending cuts.
Currently at the top of the list is the Californian Institute of Technology. Harvard and Stanford University were in joined second place with Oxford close behind.
Princeton University, University of Cambridge, Massachusetts Institute of Technology (MIT), Imperial College London, University of Chicago and University of California, Berkeley were all in the top ten.