Poindexter was the son of tenant farmers in rural Tennessee. He attended Lincoln University, PA, graduating in 1924, then went on to Howard Medical School, from where he earned his M.D. in 1929. He furthered his studies at Columbia University, where he received an A.M. in microbiology in 1930, and the Ph.D. in microbiology and immunology in 1932. He received an M.P.H. in public health and tropical medicine from Harvard in 1932. Dr. Poindexter became the head of the Medical College at Howard University in 1936.
He entered military service in 1943 and had a very distinguished career as an expert on Malaria and other tropical diseases. His military service included serving as a commissioned officer in the U.S. Public Health Service (U.S.P.H.S.). In 1947, Senior Surgeon Poindexter was appointed posted to the Mission to Liberia as chief of laboratory and medical research in West Africa. The goal of the mission was to help the Liberian government in sanitation planning and the control of infectious diseases. He became director in 1948. In 1953 he was transferred to Indochina and he went on to serve in various other places such as Vietnam, Surinam, Iraq, Libya, and Sierra Leone before briefly returning to the faculty of Howard University. Poindexter published his autobiography, My World Of Reality, in 1973 in which he candidly discusses his various life experiences including dealings with racial prejudice.
- Cobb, WM (1973). "Hildrus Augustus Poindexter, M.D., M.P.H., Ph.D., D.Sc., 1901-" (PDF). J Natl Med Assoc. 65: 243–7. PMC 2609010. PMID 4573853.
- "Black Caucus of Health Workers: Awards". blackcaucus1968.blogspot.ie. Retrieved 2016-07-15.
- "Famous Brothers pg4 - Lambda Gamma Gamma Chapter, Omega Psi Phi Fraternity". www.ques-lgg.org. Retrieved 2016-07-15.
- African American Lives, edited by Henry Louis Gates, Evelyn Brooks Higginbotham. Oxford University Press, USA, 2004. ISBN 9780199882861
- Kessler, J., Kidd, J. Kidd R. & Morin, K. (1996). Distinguished African American Scientists of the 20th Century. Phoenix, AZ: Oryx Press. pp. 275–280.