Mahidol led universities in Thailand this year's rankings by the Times Higher Education, which rated the National University of Singapore the best in Asia.
Mahidol University ranked 97th in the latest rankings, with nine other Thai tertiary institutions also on the list.
King Mongkut's University of Technology Thonburi, Chulalongkorn University, Chiang Mai University, King Mongkut's Institute of Technology Ladkrabang, Suranaree University of Technology, Khon Kaen University, Prince of Songkhla University, Kasetsart University and King Mongkut's University of Technology North Bangkok were grouped below.
The survey released on Wednesday did not give exact positions for low-ranking universities and instead placed them in groups.
The National University of Singapore was named the best in Asia and was ranked in 24th place in the British journal's global university listings.
Schools in China, Hong Kong and India "have made great gains" in the Asia rankings while the majority of Japanese universities have declined, the journal said, attributing the downturn to a lack of funding and weakening ties with researchers abroad.
China's Peking University and Tsinghua University came second and third, followed by Nanyang Technological University in Singapore and the University of Hong Kong.
The University of Tokyo, Japan's only university in the top 10, remained seventh. It ranked 39th in last year's global list.
The list covered 300 higher educational institutions across Asia and the Middle East, up from 200 last year.
Japan had 69 places on the list, the most among the 24 countries covered, which included Sri Lanka, Kuwait and the Philippines for the first time. But the number of Japanese universities in the top 100 declined to 12 from 14 last year.
The school rankings are based on 13 indicators, including citations and international outlook.