The Auxiliary Medical Service (AMS) is a government department formed under the Security Bureau with a staff of 95 civil servants. It manages a government-financed auxiliary service with 4 418 volunteers. In addition to doctors and nurses, all of its members are qualified Disaster Medical Assistants. Its main role is to reinforce medical, health and ambulance services during emergencies and to provide backup during ordinary times. The Director of Health is AMS's commissioner and is responsible to the Chief Executive for the efficient running of the service.

AMS makes sure it is prepared at all times to deal with unexpected and urgent situations affecting public health. AMS members receive training on how to tackle outbreaks of infectious diseases such as the avian flu and influenza. They take part regularly in joint exercises with the Department of Health. Up to 1 200 AMS members have received this kind of training so far. AMS has set up a Health Protection Unit which formulates plans for dealing with disease outbreaks of pandemic proportions. The unit also holds drills and helps promote the 'Building Healthy Cities' programme.

AMS pays great attention to its Voluntary Service Programme. Its first aid bicycle team provides first aid services along the cycling track between Tai Wai and Tai Po and mans the first aid posts at cycling tracks in Ma On Shan, Sha Tin and Tai Po during weekends and public holidays. Instructors from the Voluntary Service Group run programmes on first aid and on safety at schools for teachers, students and their parents in Sha Tin, Yuen Long, Tuen Mun, Wong Tai Sin and Kowloon City. AMS has also published a manual entitled 'Our Victory Over Infections', which teaches people how to observe proper hygiene and how to avoid contracting infectious diseases. It received a 'Caring Organisation' award from the Hong Kong Council of Social Services in recognition of its community work.