Mechai Viravaidya "also known as "the condom king," is Thailand's famous fighter for family planning and safe sex. A health economist from a wealthy family and the founder of the Population and Community Development Association, Mechai is best known for his use of humor and unorthodox methods in focusing the public's attention on public health." 
- Population and Development International (PDI), Bethesda, MD, USA. President.
- International Rice Research Institute (IRRI), Philippines, Trustee.
- Population Services International, Inc., Washington DC, USA, Trustee.
- Member of the Asialink Council, see Asialink Centre
- Trustee, Ramon Magsaysay Award 
Past National: Affiliations
- Tourism Authority of Thailand, Chairman.
- National Public Information Committee, Chairman.
- National Sports Authority, Chairman.
- Cultural Promotion Fund Committee, Chairman.
- Advisory Committee on AIDS to the Prime Minister, Chairman.
- Mahidol University, Trustee.
- Ramkhamhaeng University, Trustee.
- Silpakorn University, Trustee.
- National Environmental Board, Director.
- National Cultural Commission, Director.
- National Family Planning Board, Director
- Narcotics Control Board, Director
- National Research Council of Thailand on Social Sciences, Director
- National Rural Development Committee (NRDC), Director.
Past International Affiliations
- Population Council, New York, NY, USA, Trustee.
- John D. and Catherine T. MacArthur Foundation, World Population Program Advisory Committee, Chicago, USA.
- World Wide Fund for Nature (WWF), Gland, Switzerland, Trustee.
- Global Commission on AIDS, World Health Organization, Geneva, Switzerland, Member.
- The International Jury for the J. Paul Getty Wildlife Conservation Prize, Washington DC, USA, Director.