Trinity College has dropped 10 places in a global universities' league table.
The latest QS World Rankings show Trinity has fallen to joint 71st place, while UCD held its own at 139th position.
NUI Galway improved its position to move up four places to tie for 280th place.
Meanwhile four of the 10 best universities in the world are in the UK, with Imperial College London sharing second place with Cambridge.
Massachusetts Institute of Technology in the US topped the list.
