Professor Smallwood is Emeritus Professor of Medicine, University of Melbourne. As Professor of Medicine within the University of Melbourne, he was Head of the Department of Medicine, Chairman of the Division of Medicine and Director of Gastroenterology at the Austin and Repatriation Medical Centres. Professor Smallwood was President of the Royal Australasian College of Physicians from 1996 to 1998 and was Chief Medical Officer of Australia from 1999 to 2003.
Professor Smallwood has served as a chair of a large number of organisations including the NH&MRC, the National Influenza Pandemic Advisory Council, the National Health Information Management Advisory Council, the National Health Priority Action Council, the National Blood Authority and the Ministerial Taskforce for Cancer in Victoria. Professor Smallwood is currently President of the Australian Medical Council. He was until 2010 a member of the Board of Governance of the Victorian Health Promotion Foundation and, until 2009, a director of the Murdoch Children’s Research Institute. He was a director of the Australian Stem Cell Centre.