Archibald Douglas Pringle, medical practitioner, was the son of Robert Pears Pringle and his wife Martha Eliza Botha. He grew up in the Eastern Cape and studied medicine at the University of Aberdeen, Scotland, where he qualified as Bachelor of Medicine (MB) and Bachelor in Surgery (ChB) in 1904. Upon his return to South Africa he was appointed in October 1904 as assistant medical officer at the Government Asylum in Pietermaritzburg (later the Pietermaritzburg Mental Hospital), under Dr James Hyslop*. He was registered to practice medicine in the Colony of Natal that same year. In 1906 and 1907 he published two papers on individual psychiatric patients in the British Journal of Psychiatry.
While he remained in Natal, Pringle registered to practice medicine in the Transvaal in 1911. In 1916 he was awarded the degree Doctor of Medicine (MD) by the University of Aberdeen, with a thesis entitled A contribution to the study of the Bantu race (Zulus) in Natal, with reference to (1) their mode of living, racial customs and social conditions and (2) their physical and mental diseases. That same year he moved to the Witwatersrand, where he worked at the Simmer and Jack Mine for a while and in 1917 became medical superintendent of the Sprinkell Miners' Phthisis Sanatorium, maintained by the Chamber of Mines at Modderfontein, near Johannesburg. The next year his career was interrupted for a while by the last phase of World War 1 (1914-1918), when he was attached to the South African Military Hospital at Abbeville, France.
Back at Sprinkell after the war Pringle became an authority on tuberculosis. His publications on the subject included the following papers: 'Pulmonary tuberculosis in South Africa: Its prevalence, treatment and economic influence' (Journal of the Medical Association of South Africa, 1930, Vol. 4, pp. 453-456); 'Tuberculosis in native employees of the gold mining industry (Rand)' (British Journal of Tuberculosis, 1937, Vol. 31(3), pp. 136-140); and 'The care and after-care of the tuberculous among the European mining population of the Rand' (Ibid, 1937, Vol. 31(3), pp. 144-149). He remained at Sprinkell until his retirement in 1945, when he was succeeded as superintendent by his son, Maurice Archibald Pringle.
Pringle married Lucy Isobel Heslop, with whom he had four sons and a daughter. She became a mental patient and after their divorce in 1943 he married Dorothy Elsie Burridge, but had no further children.