Three Scottish universities have been ranked in the top 100 establishments in the world for scientific research.
The universities of Edinburgh, St Andrews and Dundee all made the top 100 of the Leiden ranking 2011/2012.
The list uses various indicators to assess the quality and importance of scientific research at 500 of the world's top universities.
In total, six Scottish universities made it on to the table.
Other Scottish institutions making it on to the list were the University of Glasgow, the University of Aberdeen and the University of Strathclyde in Glasgow.
The ranking found St Andrew's University - Scotland's oldest - as among the world's leading universities for international research collaboration.
Image: University of St Andrews, Wiki Creative Commons.
