Bangkok Hospital and Bangkok Airways part of the rich legacy of surgeon-turned businessman
Dr Prasert Prasarttong-Osoth, the founder of Thailand’s largest private hospital business as well as an airline that put Koh Samui on the global tourism map, has passed away at the age of 93.
Dr Prasert died on Tuesday after being treated for an unspecified condition for an extended period, according to Bangkok Dusit Medical Services Plc (BDMS). His funeral will be held at Wat Thepsirin in Bangkok.
Born in Bangkok on March 22, 1933, Prasert was the fourth of 10 children of Thongyu and Boonrod Prasarttong-Osoth, formerly known as Changboonchu.
He completed his primary and secondary education at Assumption College Bang Rak before studying at Triam Udom Suksa School, followed by the pre-medical programme at Chulalongkorn University, until March 1960.
After earning his medical degree from Siriraj Hospital, Mahidol University, he worked as a surgeon at Siriraj Hospital for five years, but a growing interest in business drew him to other activities including construction and oil exploration.
He got into the hospital business in 1972 by founding Bangkok Hospital, which expanded gradually and became Bangkok Dusit Medical Services Plc. The company was listed on the Stock Exchange of Thailand in 1991.
Today BDMS operates the largest private healthcare network in Thailand and Cambodia with 58 hospitals under six brands: Bangkok Hospital, Samitivej Hospital, BNH Hospital, Phyathai Hospital, Paolo Hospital and Royal Hospital Group (Cambodia).
Dr Poramaporn Prasarttong-Osoth, the fourth daughter of Dr Prasert, took over as chief executive of BDMS in September 2020.
Bangkok Airways started in 1968 when Dr Prasert established Sahakol Air as a department in his company, Krungthep Sahakol. The airline operated charter flights based on market demand.
In 1984, the airline was spun off as a separate company operating as Bangkok Airways. In 1986 it began scheduled flights from Bangkok to Nakhon Ratchasima, Surin and Krabi, using an 18-seat aircraft.
Business really began to take off after the company decided to build its own airport on the southern island of Koh Samui in Surat Thani. Bangkok-Samui flights began in 1989, and the company has enjoyed a near-monopoly on the route ever since. Bangkok Airways was listed on the SET in 2014.
The airline also operates other domestic and international routes, linking Bangkok with major heritage tourism sites such as Siem Reap in Cambodia, Luang Prabang in Laos, and Xi’an, Guilin, Jinghong and Chiang Rung in China.
Puttipong Prasarttong-Osoth, Dr Prasert’s eldest son, has been the chief executive of Bangkok Airways since 2019.
In the annual ranking of Thailand’s richest stock investors in 2025, Dr Prasert placed third, with total shareholdings worth 33.1 billion baht, from his 9.2% stake in BDMS and 11.4% stake in Bangkok Airways.
Forbes magazine this year ranked him as Thailand’s seventh-richest person, with an estimated net worth of around $3.6 billion as of April 21.
Dr Prasert married Wanli Posayachinda in 1963 and they had four children, while a fifth was adopted.
The body will be placed at Sala Klang Nam at Wat Thepsirin, with a bathing ceremony at 3pm on Wednesday, followed by a royal bathing rite at 5pm, and funeral prayers at 6pm. Prayers will continue from April 23-28 at 6.30pm each day. The body will then be kept for 100 days. The family has asked the public to refrain from sending wreaths.