od 1861 do śmierci w 1886 wykładał w Bellevue Hospital Medical College, a od 1861 do 1868 wykładał patologię i medycynę kliniczną w Long Island College Hospital. Był przewodniczącym New York Academy of Medicine od 1872 do 1885, we 1884 przewodniczył American Medical Association.
Na jego cześć nazwano jedno z patologicznych zjawisk stwierdzanych przy osłuchiwaniu serca – szmer Austina Flinta.
Prace Prize Essay. On the variations of pitch in percussion and respiratory sounds, Buffalo, 1852. Clinical reports on chronic pleurisy, Buffalo, 1853. Clinical report on dysentery, Buffalo, 1853. Physical exploration and diagnosis of diseases affecting the respiratory organs, Philadelphia, 1856. On cardiac murmurs, Am J Med Sci, 1862, 44:29-54. Compendium of percussion and auscultation, New York, 4th edition, 1869. Clinical report on hydro-peritoneum based on an analysis of forty-six cases, The American Journal of the Medical Sciences, Hagerstown, Maryland, 1863, 45: 306-339 Contributions relating to the causation and prevention of diseases, and to camp-diseases, New York, 1867. A practical treatise on the diagnosis, pathology, and treatment of diseases of the heart, Philadelphia, 1859. A Treatise on the Principles and Practice of Medicine, 1866. Contributions relating to the causation and prevention of diseases, and to