Austin Coates wrote extensively on topics related to the Asia-Pacific region, particularly Hong Kong and Macau. He was first connected to the East through his service for the Royal Air Force intelligence in India, Burma, Malaysia and Indonesia in the Second World War. After the war, he worked for the Hong Kong government as Assistant Colonial Secretary and Magistrate in the New Territories from 1949 to 1956. As a magistrate, he gained insight on the Chinese customs and character, and he applied Chinese laws to solve many of his cases.
After Hong Kong, he was the Chinese Affairs Officer in Sarawak from 1957 to 1959; First Secretary of the British High Commission, Kuala Lumpur and Penang from 1959 to 1962. In 1962, he left the British civil service to concentrate on writing. In 1965, he settled in Hong Kong and continued travelling and writing extensively.
Coates was the guest of many prominent Asians, among them the Tagore family, the Indian painter Jamini Roy and Mahatma Gandhi. After his visit with Gandhi, he decided that understanding between East and West was one of the most important goals in the world.
- Prelude to Hong Kong (London: Routledge and Kegan Paul; second edition as Macao and the British, 1637–1842 Hong Kong: Oxford University Press, 1988, 234 pp;
- City of Broken Promises, Hong Kong, Oxford University Press, 2nd edition 1987 (1st edition: 1967), 314 pp. A novel based on the life of Martha Merop, a Chinese orphan in Macao who rose to great success in business and her liaison with Thomas Kuyck van Mierop, a principal of the British East India Company.
- Myself a Mandarin (London: Frederick Muller, 1968), describes the author's experience as a special Magistrate in the New Territories;
- Rizal, Philippine Nationalist and Martyr, 1968, Oxford University Press. José Rizal is the national hero of the Philippines.
- A Macau Narrative, Hong Kong, Oxford University Press, 2nd edition 1999 (1st edition: 1978), 146 pp., preface by Cesar Guillen-Nunez
- China Races Oxford University Press (China), 1984, a history of racing on the China Coast commissioned by the Royal Hong Kong Jockey Club.
- China, India and the Ruins of Washington (New York: John Day. 1972), discusses the longevity of the Chinese and Indian civilisations in contrast to the Western civilisation.
- A Mountain of Light: The Story of the Hongkong Electric Company
- Whampoa: Ships on the Shore (Hong Kong: SCMP. 1980), about the founding of the Hongkong & Whampoa Dock Company and the transformation of Hong Kong from a sleepy little village to the seventh biggest port of the world.
- Quick Tidings of Hong Kong (Hong Kong: Oxford University Press. 1990 A History of telecommunications in Hong Kong.
- Numerology, paperback ISBN 0-8216-2506-3
- Islands of the South
- Western Pacific Islands (The Corona library)
- Personal and Oriental
- Invitation to an Eastern Feast
- The Road (London: Hutchinson & Co, 1957), describes his personal experience as an insignificant traveller in the East; starting from Japan, then to Hong Kong, Philippines, Burma, India, Pakistanl and Istanbul.
- The Commerce in Rubber: The First 250 Years
- Basutoland (Corona library)
- Portuguese Roots in Africa