Although Abraham Flexner (1866-1959) is well known as the author of Medical Education in the United States and Canada: A Report to the Carnegie Foundation for the Advancement of Teaching--so well known that this publication's better-known shorthand title is "the Flexner Report"--for many the "real" Flexner remains something of a mystery. Many today believe that he was overly rigid in his goals for medical education and that he did not adequately champion the rights of women and African Americans, harsh criticisms in late-20th-century America. But who really was Abraham Flexner? The author discusses Flexner the education reformer and the man, highlighting his early years in Louisville and his relationship with his family and his wife, his later graduate work and associations with the Carnegie Foundation for the Advancement of Teaching and the General Education Board, and his then-radical proposals for the reshaping of American medical education. Flexner's attitudes toward women and African Americans are also reviewed, and the author shows that Flexner encouraged both women and blacks to pursue higher education in general and medical careers in particular. Finally, the author discusses Flexner's feelings about his own Jewishness and anti-Semitism, his political beliefs, and his personal attributes as described both by the press and by his friends.