In the Field of Public Health: Dr. Wiwat Rojanapithayakorn, while serving as Director of the Office of Communicable Disease Control Region 4 in Ratchaburi, Thailand in 1989, initiated the “100% Condom Use Programme” which has been recognized worldwide as one the most successful HIV/AIDS prevention tools.The principle of the 100% Condom Use Programme is based on cooperation among all stakeholders, government authorities, provincial governors and officers, healthcare personel and commercial sex business operators. The key success factor was empowering commercial sex workers to refuse service if customers do not use condoms: No Condom – No Sex.  This led to the effective reduction of HIV infection among commercial sex workers and has proven effective in preventing sexual transmission of HIV in the general public.  This programme was then expanded throughout Thailand.  It played a crucial role in controlling of the spread of HIV infection, resulting in the reduction of new HIV cases from 400,000 cases in 1991 down to less than 14,000 new cases in 2001.  Dr. Wiwat actively advocated this programme internationally, including in Cambodia, Vietnam, Philippines, China, Myanmar, Mongolia and Lao PDR. His work has been recognized around the world.  Many international organizations, including the World Health Organization, World Bank, UNAIDS, USAID, recognize this 100% Condom Use programme as one of the most successful HIV prevention tools. It is also a successful example of behavioural change and social empowering in the public. This work has positively impacted several hundred millions of lives around the world.Mr. Mechai Viravaidya founded the Community-based Family Planning Services in 1974, currently known as the Population and Community Development Association (PDA), to provide family planning education for women in rural areas.  He has been a tireless proponent of the use of condoms to prevent unwanted pregnancies through unique communication campaigns, which have demystified condoms, previously a taboo subject and an unspoken issue in the public, so that they are now commonly-used items.  He is known as Mr. Condom and condoms are commonly referred to by his name.His work played a crucial role in awakening the government and civil society to address this issue.The widespread use of condoms also helps control the spread of sexually-transmitted diseases.  When the HIV epidemic hit Thailand and other countries in 1980s and 1990s, Mr. Mechai played a major role in developing national HIV communication and prevention campaigns that have a number of important elements, including behavioural change promotion and the support of the 100% Condom Use Programme. The success of Thailand in controlling the spread of HIV has been used as an example in the international public health arena. Mr. Mechai’s pioneering work in demystifying and advocating the use of condoms has contributed towards the health of several hundreds of million of people living around the world.          Their Majesties the King and the Queen have graciously consented to preside over the Presentation Ceremony of the Prince Mahidol Award 2009 at the end of January 2010 at the Chakri Throne Hall.           The Prince Mahidol Award Foundation was established to commemorate the centenary of the birth of His Royal Highness Prince Mahidol of Songkla on 1st January 1992.The Foundation is under Royal Patronage, with Her Royal Highness Princess Maha Chakri Sirindhorn as president.The Prince Mahidol Award is conferred annually upon individual(s) or institution(s) demonstrating outstanding and exemplary contribution to the advancement of medical and public health services throughout the world. Each Award consists of a medal, a certificate and US$50,000.  In the past 17 years, 51 individuals, groups of individuals, and institutions have received the Prince Mahidol Award. Among them, two subsequently received the Nobel Prize in Physiology or Medicine, namely Professor Dr. Barry James Marshall and Professor Dr. Harald zur Hausen.