According to ISNA, Dr Muhammad Javad Dehghani, indicated that Bu-Ali Sina University is placed 22nd amid Iran's universities in the Leiden Ranking. "Leiden is a valid system for evaluating universities that ranks and evaluates the best universities in the world based on authentic and scientometric indices. In 2018, universities all around the world were ranked based on nine indices in the form of two general standards of scientific authority and scientific diplomacy. These evaluations have used the universities' scientific output in years 2013 to 2016 based on the Web of Science's database. The scientific criterion (scientific impact) has benefited from indices like, one percent top articles, 5 percent top articles, 10 percent top articles and 50 percent top articles." he added.

"The criterion for scientific diplomacy also used indices like scientific cooperation, global cooperation, industrial cooperation, scientific cooperation with a geographical distance of less than 100 kilometers and scientific cooperation with a geographical distance of more than 5000 kilometers. " he reminded.

"Survey of nation's universities in the Leiden ranking shows that the performance of these universities has improved through the years. Iran, similar to the previous years, holds the first place in the number of best universities amid Islamic nations. Compared to other countries in the region like Saudi Arabia, Turkey and Malaysia, Iran also has had the best development in the number of universities amongst the best universities of the world." the ISC administrator remarked.

"In Leiden's 2018 ranking, Turkey has 19 universities, Malaysia has 5 and Saudi Arabia has 4 universities and this number for aforementioned countries has been 16, 5, and four cases in that order in 2017." He added.

The chart below shows the turnover of the numbers of nation's universities in Leiden Ranking.

"In 2018, University of Tehran , University of Amir Kabir, Tehran University of Medical Sciences, Sharif University of Technology, Tarbiat Modares University, Isfahan University of Technology, Iran University of Science and Technology, Ferdowsi University of Mashhad, Shiraz University, Tabriz University, Shahid Beheshti Universe of Medical Science, Tehran Science and Research University, Shahid Beheshti University, Khaje Nasir University of Technology, Isfahan University, Guilan University, Kashan University, Isfahan University of Medical Sciences, Shiraz University of Medical Sciences, Tabriz University of Medical Sciences, Mashahd University of Medical Sciences, Bu-Ali Sina University and Kerman Shahid Bahonar University were present," Dehghani continued.

"In 2017, Universiti of Tehran, University of Amir Kabir, Tehran University of Medical Sciences University, Sharif University of Technology, Tarbiat Modares University, Isfahan University of Technology, Iran University of Science and Technology, University of Shiraz, Ferdowsi University of Mashhad, Tabriz University, Shahid Beheshti University of Medical Sciences, Tehran Science and Research University, Shahid Beheshti University, Khaje Nasir University of Technology, Isfahan University, Isfahan University of Medical Sciences, Guilan University and Shiraz University of Medical Sciences were placed in the rankings," he then added.

"In 2016's Leiden Ranking, 14 universities of Tehran, University of Amir Kabir, Tehran University of Medical Sciences, Sharif University of Technology, Tarbiat Modares University, Isfahan University of Technology, Shiraz University, Ferdowsi University of Mashhad, Tabriz University, Shahid Beheshti University, Shahid Beheshti University of Medical Sciences, Khaje Nasir University of Technology and University of Isfahan were in this ranking," the SCI administrator said.

"In 2015, the number of nation's universities in this ranking reached 13. Isfahan University of Technology, Amir Kabir University, Sharif University of Technology, Tabriz University, Iran University of Science and Technology, University of Tehran, Shahid Beheshti University, Tarbiat Modares University, Shiraz University, Ferdowsi University of Mashhad, Tehran University of Medical Sciences, Shahid Beheshti University of Medical Sciences and Islamic Azad University were present in this ranking in 2015," he continued.

"In 2014, the number of Iranian universities that were present in this ranking reached 12 including universities of Amir Kabir, Tabriz University, , Sharif University of Technology, Iran University of Science and Technology, University of Tehran, Shahid Beheshti University, Tarbiat Modares University, Ferdowsi University of Mashhad, Shiraz University, Tehran University of Medical Sciences and Islamic Azad University," the ISC administrator declared.

In year 2012, no universities of the country were present amid the best universities of the world and in 2013; five universities of Amir Kabir, Sharif, Tarbait Modares, Tehran and Tehran's Medical Sciences were placed in this ranking for the first time. The global performance of nation's universities according to the index of scientific production in Leiden Ranking is shown in the table below.