Edinburgh University has been named as the institution which used the second highest number of animals for testing in the UK in 2014.
The historic university came behind Oxford University, which used 226,739 in its laboratories.
Edinburgh University used 200,861 animals in testing in 2014.
University College London came in third (176,901), King's College London fourth (165,068) and Cambridge fifth (160,557).
The figures have been compiled by anti-vivisection organisation Cruelty Free International through freedom of information requests.
Among the animals tested were rats, mice, birds, frogs, fish, ferrets, guinea pigs, rabbits, sheep and monkeys.
Dr Katy Taylor, director of science at Cruelty Free International, formerly the British Union for the Abolition of Vivisection (BUAV), said: "The public will be shocked to learn that five of the UK's leading universities are responsible for testing on almost one million animals, despite an increasing number of universities recognising this isn't the way to do research.
"We urge them to leave this archaic practice behind and move towards developing innovative and humane research methods for the 21st century."
Monkey experiments conducted at some universities were said to involve animals being deprived of food or water, having electrodes implanted in their skulls or limbs, and being blasted with loud noise while trapped in a box, claimed Cruelty Free International.
The campaign group claimed other experiments included rats being injected with acid to cause brain damage, and pregnant sheep being injected with testosterone twice a week or having their ovaries punctured during surgery.
Testing in universities accounts for around half of all animal experimentation in the UK according to the Home Office.
An Edinburgh University spokesman said: "The university is the largest university in Scotland and one of the UK's top-rated research universities.
"A small proportion of our research involves the use of animals as a vital component of the quest to advance medical, biological and veterinary science.
"We use animals in research programmes, predominately rodents and fish (97%) only when their use is justified on scientific, ethical and legal grounds, and when no alternatives are available.
"All such work is strictly regulated and carried out under licences, which are reviewed and approved by the Home Office and are issued only if the potential benefits of the work are likely to outweigh the effects on the animals concerned."