Dr Tan Chi Chiu graduated from the National University of Singapore in 1983. He pursued specialist training in Internal Medicine and obtained his Memberships of the Royal Colleges of Physicians of United Kingdom and Ireland, as well as Master of Medicine in Internal Medicine, in 1988. He specialised in Gastroenterology and was accorded the Fellowship of the Academy of Medicine in Gastroenterology in 1993 and recognised by the Ministry of Health as a specialist in Gastroenterology. He was further conferred the Fellowships of the Royal Colleges of Physicians of Edinburgh and London in 1996 and 1998 respectively.

Dr Tan trained in the Singapore General Hospital and National University Hospital in Singapore. He spent two years in the United Kingdom (affiliated to the University of Nottingham) as an advanced specialist trainee in therapeutic endoscopy and laser endoscopy. He was also attached to the Endoscopy Department of the Academic Medical Centre in Amsterdam for enhanced exposure to techniques of Endoscopic Retrograde Cholangio-Pancreatography (ERCP).

He was appointed Consultant in Gastroenterology and Medicine in the Department of General Medicine of Tan Tock Seng Hospital in 1995, where he went on to found and head the Gastroenterology Unit. He was also Chairman of the Endoscopy Committee of the hospital. Today he is still a Visiting Consultant to Tan Tock Seng Hospital, where he supervises and trains junior consultants in endoscopic procedures. Dr Tan has conducted original research in Gastroenterology and Hepatology and published many articles in peer reviewed medical journals. Dr Tan is an elected member of the Singapore Medical Council, where he is the Chairman of the Ethics Committee.

Dr Tan is also an active and well-known figure in the youth development and community service scene in Singapore. He has been involved in numerous overseas humanitarian, scientific and community aid expeditions, to countries such as Indonesia, Laos, India, Mongolia and Chile. Dr Tan received several awards for his work in this area including the Singapore Youth Award (Youth Development/Community Service) in 1996 and both the Excellence for Singapore Award and the Commonwealth Youth Programme Asia Award for Excellence in Youth Work in 1997. His 'Operasi Raleigh Batam' project won the Pan-Commonwealth Youth Service Award in 1998.

Dr Tan led the Singapore Armed Forces (SAF) medical missions to the Philippines earthquake disaster in 1990 and to the Gulf War in 1991. For these he was decorated with the SAF's Overseas Service (Non-operational) Medal (Philippines earthquake) and the SAF Overseas Service (Operational) Medal (Gulf War). He also received the British Gulf War Medal and the Saudi Arabian King Abdul Aziz Medal.