This essay outlines the historical context in which the Feighner criteria emerged; reconstructs, as far as possible, the process by which the criteria were developed; and traces the influence the criteria had on subsequent developments in American psychiatry. In the 1950s, when American psychiatry under psychoanalytic dominance had little interest in psychiatric diagnosis, Edwin Gildea recruited to the Department of Psychiatry at Washington University faculty who advocated a medical model for psychiatry in which diagnosis had a central role. In 1967, at the urging of the then-resident John Feighner, a discussion group led by Eli Robins and including Sam Guze, George Winokur, Robert Woodruff, and Rod Muñoz began meeting with the initial goal of writing a review of prior key contributions to psychiatric diagnosis. In their meetings over the next year, the task soon shifted to the development of a set of new diagnostic criteria. For three diagnoses, major depression, antisocial personality disorder, and alcoholism, the authors could identify the original criteria from which this group worked and the rationale for many of the changes they introduced. Published in 1972, the Feighner criteria were soon widely cited and used in research, and they formed the basis for the development of the Research Diagnostic Criteria, which in turn were central to the development of DSM-III. The team that developed the Feighner criteria made three key contributions to psychiatry: the systematic use of operationalized diagnostic criteria; the reintroduction of an emphasis on illness course and outcome; and an emphasis on the need, whenever possible, to base diagnostic criteria on empirical evidence.