Dr Prasert, founder of BDMS and Bangkok Airways, dies aged 93

Dr Prasert Prasarttong-Osoth, one of Thailand’s leading stock-market billionaires and the businessman behind Bangkok Dusit Medical Services (BDMS), Bangkok Airways and other ventures, died on Tuesday (April 21) at the age of 93 after undergoing medical treatment for several years.

His body is being laid at Wat Thepsirin in Bangkok. A water-pouring ceremony will be held on Wednesday (April 22) at 3pm, followed by the royal bathing rite at 5pm and Abhidhamma prayers at 6pm. 

From April 23 to 28, Abhidhamma prayers will be held daily at 6.30pm, after which the body will be kept for 100 days.

Biography of Dr Prasert Prasarttong-Osoth

Dr Prasert Prasarttong-Osoth was born on March 22, 1933, and was 93 years old. He was born into the Changboonchu family, which later changed its surname to Prasarttong-Osoth.

He was the son of Thongyu and Boonrod Prasarttong-Osoth, and the fourth of 10 siblings. He married Wanli Posayachinda on December 26, 1963.

He had four children: Puttipong Prasarttong-Osoth, Somruthai Prasarttong-Osoth, Ariya Prasarttong-Osoth and Dr Poramaporn Prasarttong-Osoth. He also had an adopted son, Capt Smith Prasarttong-Osoth.

Prasert completed his primary and secondary education at Assumption College Bang Rak before studying at Triam Udom Suksa School, then the pre-medical programme at the Faculty of Science, Chulalongkorn University, until March 1960.

He earned a medical degree from Siriraj Hospital, Mahidol University. He also completed the National Defence College programme, Class 1, in 1989, and later received honorary doctorates in marketing from Christian University in 2007, in aviation business administration from Kasem Bundit University in 2007, and in management from Rajamangala University of Technology Thanyaburi in 2016.

Career history

Prasert began his working life in the surgery department at Siriraj Hospital as a resident doctor, a role he held for only five years. He later became chairman of Krungthep Sahakol and an adviser to Union Oils, earning recognition more for his role in the construction sector and in coordinating with the United States on oil exploration in Thailand than for his medical career.

He was later elected president of the Siriraj Medical Alumni Association, became a member of the National Legislative Assembly on March 15, 1991, and a senator on March 22, 1992.

Prasert was also the owner of Bangkok Airways and BDMS, and served as chief executive officer of BDMS. He also expanded into digital television through PPTV, a digital TV station offering variety, knowledge, entertainment and news programmes under the concept “PPTV Life is Awesome”.

In 2016, Prasert retained his position as Thailand’s richest stock investor for a fourth consecutive year. He first rose to the top of the ranking in 2013, with total shareholdings valued at 67.24 billion baht.

In the 2025 ranking of Thailand’s richest stock investors, Prasert ranked third, with total shareholdings worth 33.06 billion baht, down 34.74%. The holdings consisted of a 9.18% stake in BDMS and an 11.38% stake in Bangkok Airways.