When Raphael Cilento drafted his unpublished autobiography, he called it ‘The World, My Oyster’. Some of the other titles he considered—such as ‘Confessions of an International Character’, ‘20th Century Spotlight’, ‘Mankind in the Raw’ and ‘Tapestry of Humanity’—similarly evoked his international career. Other alternatives—such as ‘Topical Confessions of a Tropical Doctor’, ‘Where the Fever Lurks, There Lurk I’ and ‘The Southern Cross is Hard to Bear’—instead suggest how Cilento, an Australian doctor, colonial official and administrator, remained preoccupied with health and sickness across the tropical spaces of northern Australia, the Pacific Islands and South-East Asia.1 Like many public health experts in the twentieth century, Cilento enjoyed significant mobility across the imperial and international professional networks of the time. Between 1918 and 1950, he studied and worked in northern Australia, British Malaya, New Guinea and other Pacific Island colonies, as well as Europe, the United States, Latin America, Palestine and other states in Asia and the Middle East. He stayed for several years in some places, as in the Mandated Territory of New Guinea in the mid-1920s, while elsewhere he simply passed through as a student, a conference participant or a member of an international health survey.Cilento’s memoir titles and the breadth of his colonial and international experience are, at first glance, striking for a man who dedicated his career to national health and racial fitness. In the 1920s, even as knowledge of the causes and preventability of disease spread among the medical profession and the public, the belief that European residence in tropical climates led to sickness in the short term and to racial deterioration over a few generations still cast doubt on the realisation of the White Australia Policy.